diff --git a/azure-pipelines.yml b/azure-pipelines.yml
index 255116c2cf6b..3208ba7e96fc 100644
--- a/azure-pipelines.yml
+++ b/azure-pipelines.yml
@@ -255,7 +255,9 @@ jobs:
       - bash: |
           set -euo pipefail
           eval "$(./dev-env/bin/dade-assist)"
-          bazel test --config scala_2_13 //libs-scala/ports/...
+          bazel build --config scala_2_13 //libs-scala/...
+          # gatling-utils tests fail with a ClassNotFoundException for scala.collection.SeqLike
+          bazel test --config scala_2_13 -- //libs-scala/... -//libs-scala/gatling-utils/...
         displayName: 'Build'
         env:
           DAML_SDK_RELEASE_VERSION: $(release_tag)
diff --git a/bazel_tools/proto.bzl b/bazel_tools/proto.bzl
index b17729b2170e..20d211333fe3 100644
--- a/bazel_tools/proto.bzl
+++ b/bazel_tools/proto.bzl
@@ -10,6 +10,7 @@ load("@io_bazel_rules_scala//scala:scala.bzl", "scala_library")
 load("@os_info//:os_info.bzl", "is_windows")
 load("@rules_pkg//:pkg.bzl", "pkg_tar")
 load("@rules_proto//proto:defs.bzl", "proto_library")
+load("@scala_version//:index.bzl", "scala_major_version_suffix")
 
 # taken from rules_proto:
 # https://github.com/stackb/rules_proto/blob/f5d6eea6a4528bef3c1d3a44d486b51a214d61c2/compile.bzl#L369-L393
@@ -177,10 +178,10 @@ def _proto_scala_srcs(name, grpc):
 def _proto_scala_deps(grpc, proto_deps):
     return [
         "@maven//:com_google_protobuf_protobuf_java",
-        "@maven//:com_thesamet_scalapb_lenses_2_12",
-        "@maven//:com_thesamet_scalapb_scalapb_runtime_2_12",
+        "@maven//:com_thesamet_scalapb_lenses_{}".format(scala_major_version_suffix),
+        "@maven//:com_thesamet_scalapb_scalapb_runtime_{}".format(scala_major_version_suffix),
     ] + ([
-        "@maven//:com_thesamet_scalapb_scalapb_runtime_grpc_2_12",
+        "@maven//:com_thesamet_scalapb_scalapb_runtime_grpc_{}".format(scala_major_version_suffix),
         "@maven//:io_grpc_grpc_api",
         "@maven//:io_grpc_grpc_core",
         "@maven//:io_grpc_grpc_protobuf",
diff --git a/bazel_tools/runfiles/src/main/scala/com/digitalasset/daml/bazeltools/BazelRunfiles.scala b/bazel_tools/runfiles/src/main/scala/com/digitalasset/daml/bazeltools/BazelRunfiles.scala
index 60cc12568dea..544e6b01b136 100644
--- a/bazel_tools/runfiles/src/main/scala/com/digitalasset/daml/bazeltools/BazelRunfiles.scala
+++ b/bazel_tools/runfiles/src/main/scala/com/digitalasset/daml/bazeltools/BazelRunfiles.scala
@@ -27,7 +27,7 @@ trait BazelRunfiles {
       val workspacePathString = MainWorkspacePath
         .resolve(path)
         .toString
-        .replaceAllLiterally("\\", "/")
+        .replace("\\", "/")
       val runfilePath = Option(Runfiles.create.rlocation(workspacePathString))
       Paths.get(runfilePath.getOrElse(throw new IllegalArgumentException(path.toString)))
     } else
diff --git a/bazel_tools/scala.bzl b/bazel_tools/scala.bzl
index 4220cb70fe96..abf46f4ebf84 100644
--- a/bazel_tools/scala.bzl
+++ b/bazel_tools/scala.bzl
@@ -42,6 +42,7 @@ version_specific = {
         "-Xlint:unsound-match",
         "-Xlint:by-name-right-associative",  # will never be by-name if used correctly
         "-Xfuture",
+        "-language:higherKinds",
     ],
 }
 
@@ -152,8 +153,8 @@ default_compile_arguments = {
     "unused_dependency_checker_mode": "error",
 }
 
-silencer_plugin = "@maven//:com_github_ghik_silencer_plugin_2_12_12"
-silencer_lib = "@maven//:com_github_ghik_silencer_lib_2_12_12"
+silencer_plugin = "@maven//:com_github_ghik_silencer_plugin_{}".format(scala_version_suffix)
+silencer_lib = "@maven//:com_github_ghik_silencer_lib_{}".format(scala_version_suffix)
 
 default_initial_heap_size = "128m"
 default_max_heap_size = "1g"
diff --git a/ledger-api/rs-grpc-akka/BUILD.bazel b/ledger-api/rs-grpc-akka/BUILD.bazel
index c0b3aa7ce4a8..ad4b3563939c 100644
--- a/ledger-api/rs-grpc-akka/BUILD.bazel
+++ b/ledger-api/rs-grpc-akka/BUILD.bazel
@@ -6,6 +6,10 @@ load("//bazel_tools:scala.bzl", "da_scala_binary", "da_scala_library", "da_scala
 da_scala_library(
     name = "rs-grpc-akka",
     srcs = glob(["src/main/scala/**/*.scala"]),
+    scala_deps = [
+        "@maven//:com_typesafe_akka_akka_actor",
+        "@maven//:com_typesafe_akka_akka_stream",
+    ],
     tags = ["maven_coordinates=com.daml:rs-grpc-akka:__VERSION__"],
     visibility = [
         "//visibility:public",
@@ -13,8 +17,6 @@ da_scala_library(
     deps = [
         "//ledger-api/rs-grpc-bridge",
         "//libs-scala/concurrent",
-        "@maven//:com_typesafe_akka_akka_actor_2_12",
-        "@maven//:com_typesafe_akka_akka_stream_2_12",
         "@maven//:io_grpc_grpc_stub",
         "@maven//:org_reactivestreams_reactive_streams",
     ],
diff --git a/ledger-api/rs-grpc-akka/src/main/scala/com/digitalasset/grpc/adapter/AkkaExecutionSequencer.scala b/ledger-api/rs-grpc-akka/src/main/scala/com/digitalasset/grpc/adapter/AkkaExecutionSequencer.scala
index 241f300876c4..ce918f79db2f 100644
--- a/ledger-api/rs-grpc-akka/src/main/scala/com/digitalasset/grpc/adapter/AkkaExecutionSequencer.scala
+++ b/ledger-api/rs-grpc-akka/src/main/scala/com/digitalasset/grpc/adapter/AkkaExecutionSequencer.scala
@@ -49,10 +49,10 @@ object AkkaExecutionSequencer {
     system match {
       case extendedSystem: ExtendedActorSystem =>
         new AkkaExecutionSequencer(
-          extendedSystem.systemActorOf(Props[RunnableSequencingActor], name))(
+          extendedSystem.systemActorOf(Props[RunnableSequencingActor](), name))(
           Timeout.durationToTimeout(terminationTimeout))
       case _ =>
-        new AkkaExecutionSequencer(system.actorOf(Props[RunnableSequencingActor], name))(
+        new AkkaExecutionSequencer(system.actorOf(Props[RunnableSequencingActor](), name))(
           Timeout.durationToTimeout(terminationTimeout))
 
     }
diff --git a/ledger-api/rs-grpc-akka/src/main/scala/com/digitalasset/grpc/adapter/AkkaExecutionSequencerPool.scala b/ledger-api/rs-grpc-akka/src/main/scala/com/digitalasset/grpc/adapter/AkkaExecutionSequencerPool.scala
index c0ca0c8af687..d20fdf37a924 100644
--- a/ledger-api/rs-grpc-akka/src/main/scala/com/digitalasset/grpc/adapter/AkkaExecutionSequencerPool.scala
+++ b/ledger-api/rs-grpc-akka/src/main/scala/com/digitalasset/grpc/adapter/AkkaExecutionSequencerPool.scala
@@ -8,7 +8,6 @@ import java.util.concurrent.atomic.AtomicInteger
 import akka.Done
 import akka.actor.ActorSystem
 
-import scala.collection.breakOut
 import scala.concurrent.duration.{DurationInt, FiniteDuration}
 import scala.concurrent.{Await, ExecutionContext, Future}
 
@@ -34,7 +33,7 @@ class AkkaExecutionSequencerPool(
 
   def closeAsync(): Future[Unit] = {
     implicit val ec: ExecutionContext = system.dispatcher
-    val eventuallyClosed: Future[Seq[Done]] = Future.sequence(pool.map(_.closeAsync)(breakOut))
+    val eventuallyClosed: Future[Seq[Done]] = Future.sequence(pool.view.map(_.closeAsync).toSeq)
     Future.firstCompletedOf(
       Seq(
         system.whenTerminated.map(_ => ()), //  Cut it short if the ActorSystem stops.
diff --git a/ledger-api/testing-utils/BUILD.bazel b/ledger-api/testing-utils/BUILD.bazel
index fa3e6937f7af..0f548b1b6f66 100644
--- a/ledger-api/testing-utils/BUILD.bazel
+++ b/ledger-api/testing-utils/BUILD.bazel
@@ -6,10 +6,24 @@ load(
     "da_scala_library",
     "da_scala_test_suite",
 )
+load("//bazel_tools:scala.bzl", "silencer_plugin")
 
 da_scala_library(
     name = "testing-utils",
     srcs = glob(["src/main/scala/**/*.scala"]),
+    plugins = [
+        silencer_plugin,
+    ],
+    scala_deps = [
+        "@maven//:com_typesafe_akka_akka_actor",
+        "@maven//:com_typesafe_akka_akka_stream",
+        "@maven//:org_scalactic_scalactic",
+        "@maven//:org_scalatest_scalatest",
+        "@maven//:org_scala_lang_modules_scala_collection_compat",
+    ],
+    scalacopts = [
+        "-P:silencer:lineContentFilters=import scala.collection.compat",
+    ],
     tags = ["maven_coordinates=com.daml:testing-utils:__VERSION__"],
     visibility = [
         "//visibility:public",
@@ -26,13 +40,9 @@ da_scala_library(
         "//libs-scala/grpc-utils",
         "//libs-scala/resources",
         "@maven//:com_google_guava_guava",
-        "@maven//:com_typesafe_akka_akka_actor_2_12",
-        "@maven//:com_typesafe_akka_akka_stream_2_12",
         "@maven//:com_typesafe_config",
         "@maven//:io_grpc_grpc_core",
         "@maven//:io_grpc_grpc_netty",
-        "@maven//:org_scalactic_scalactic_2_12",
-        "@maven//:org_scalatest_scalatest_2_12",
         "@maven//:org_slf4j_slf4j_api",
     ],
 )
diff --git a/ledger-api/testing-utils/src/main/scala/com/digitalasset/ledger/api/testing/utils/MultiFixtureBase.scala b/ledger-api/testing-utils/src/main/scala/com/digitalasset/ledger/api/testing/utils/MultiFixtureBase.scala
index 8771fcfd602a..2ee69f988e23 100644
--- a/ledger-api/testing-utils/src/main/scala/com/digitalasset/ledger/api/testing/utils/MultiFixtureBase.scala
+++ b/ledger-api/testing-utils/src/main/scala/com/digitalasset/ledger/api/testing/utils/MultiFixtureBase.scala
@@ -83,7 +83,7 @@ trait MultiFixtureBase[FixtureId, TestContext]
       }
     }
 
-    val timeoutPromise = Promise[Assertion]
+    val timeoutPromise = Promise[Assertion]()
     es.schedule(
       () => timeoutPromise.failure(new TimeoutException(s"Timed out after $timeLimit")),
       timeLimit.toMillis,
@@ -103,7 +103,7 @@ trait MultiFixtureBase[FixtureId, TestContext]
 
   /** Same as forAllFixtures, nicer to use with the "test" in allFixtures { ctx => ??? } syntax */
   protected def allFixtures(runTest: TestContext => Future[Assertion]): Future[Assertion] =
-    forAllFixtures(fixture => runTest(fixture.context))
+    forAllFixtures(fixture => runTest(fixture.context()))
 
   protected def forAllFixtures(runTest: TestFixture => Future[Assertion]): Future[Assertion] = {
     forAllMatchingFixtures { case f => runTest(f) }
diff --git a/ledger-api/testing-utils/src/main/scala/com/digitalasset/ledger/api/testing/utils/MultiResourceBase.scala b/ledger-api/testing-utils/src/main/scala/com/digitalasset/ledger/api/testing/utils/MultiResourceBase.scala
index 9c113bff1c0d..492fa3e53b0f 100644
--- a/ledger-api/testing-utils/src/main/scala/com/digitalasset/ledger/api/testing/utils/MultiResourceBase.scala
+++ b/ledger-api/testing-utils/src/main/scala/com/digitalasset/ledger/api/testing/utils/MultiResourceBase.scala
@@ -5,6 +5,7 @@ package com.daml.ledger.api.testing.utils
 
 import org.scalatest.AsyncTestSuite
 
+import scala.collection.compat._
 import scala.collection.immutable
 
 trait MultiResourceBase[FixtureId, TestContext]
@@ -31,7 +32,7 @@ trait MultiResourceBase[FixtureId, TestContext]
 case class MultiResource[FixtureId, TestContext](resources: Map[FixtureId, Resource[TestContext]])
     extends Resource[Map[FixtureId, () => TestContext]] {
   override lazy val value: Map[FixtureId, () => TestContext] =
-    resources.mapValues(r => () => r.value)
+    resources.view.mapValues(r => () => r.value).toMap
   override def setup(): Unit = resources.foreach(_._2.setup())
   override def close(): Unit = resources.foreach(_._2.close())
 }
diff --git a/ledger/participant-integration-api/BUILD.bazel b/ledger/participant-integration-api/BUILD.bazel
index 130e8b2dcaac..8f82b40ffb06 100644
--- a/ledger/participant-integration-api/BUILD.bazel
+++ b/ledger/participant-integration-api/BUILD.bazel
@@ -60,6 +60,7 @@ compile_deps = [
     "@maven//:io_netty_netty_transport",
     "@maven//:net_logstash_logback_logstash_logback_encoder",
     "@maven//:org_flywaydb_flyway_core",
+    "@maven//:org_scala_lang_modules_scala_collection_compat_2_12",
     "@maven//:org_scala_lang_modules_scala_java8_compat_2_12",
     "@maven//:org_scalaz_scalaz_core_2_12",
     "@maven//:io_opentelemetry_opentelemetry_api",
diff --git a/ledger/participant-state/kvutils/app/BUILD.bazel b/ledger/participant-state/kvutils/app/BUILD.bazel
index 86177addf3ee..9b5816d6ba4d 100644
--- a/ledger/participant-state/kvutils/app/BUILD.bazel
+++ b/ledger/participant-state/kvutils/app/BUILD.bazel
@@ -49,6 +49,7 @@ da_scala_library(
         "@maven//:com_typesafe_akka_akka_stream_2_12",
         "@maven//:io_dropwizard_metrics_metrics_core",
         "@maven//:io_netty_netty_handler",
+        "@maven//:org_scala_lang_modules_scala_collection_compat_2_12",
         "@maven//:org_scala_lang_modules_scala_java8_compat_2_12",
     ],
 )
diff --git a/libs-scala/build-info/BUILD.bazel b/libs-scala/build-info/BUILD.bazel
index 8da22bba0768..08a3a67402fe 100644
--- a/libs-scala/build-info/BUILD.bazel
+++ b/libs-scala/build-info/BUILD.bazel
@@ -13,6 +13,9 @@ da_scala_library(
         "//:mvn_version_file",
     ],
     tags = ["maven_coordinates=com.daml:build-info:__VERSION__"],
+    versioned_scala_deps = {
+        "2.12": ["@maven//:org_scala_lang_modules_scala_collection_compat"],
+    },
     visibility = [
         "//:__subpackages__",
     ],
diff --git a/libs-scala/build-info/src/main/scala/com/digitalasset/buildinfo/BuildInfo.scala b/libs-scala/build-info/src/main/scala/com/digitalasset/buildinfo/BuildInfo.scala
index 2d8d23a36574..4d4e4b5b423f 100644
--- a/libs-scala/build-info/src/main/scala/com/digitalasset/buildinfo/BuildInfo.scala
+++ b/libs-scala/build-info/src/main/scala/com/digitalasset/buildinfo/BuildInfo.scala
@@ -5,7 +5,7 @@ package com.daml.buildinfo
 
 import java.io.{BufferedReader, InputStreamReader}
 
-import scala.collection.JavaConverters.asScalaIteratorConverter
+import scala.jdk.CollectionConverters._
 
 object BuildInfo {
   val Version: String =
diff --git a/libs-scala/concurrent/BUILD.bazel b/libs-scala/concurrent/BUILD.bazel
index 703baef51b57..f331a983849b 100644
--- a/libs-scala/concurrent/BUILD.bazel
+++ b/libs-scala/concurrent/BUILD.bazel
@@ -7,6 +7,7 @@ load(
     "da_scala_test",
     "lf_scalacopts",
 )
+load("@scala_version//:index.bzl", "scala_major_version", "scala_version_suffix")
 
 scalacopts = lf_scalacopts + [
     "-P:wartremover:traverser:org.wartremover.warts.NonUnitStatements",
@@ -16,7 +17,10 @@ da_scala_library(
     name = "concurrent",
     srcs = glob(["src/main/scala/**/*.scala"]),
     plugins = [
-        "@maven//:org_typelevel_kind_projector_2_12_12",
+        "@maven//:org_typelevel_kind_projector_{}".format(scala_version_suffix),
+    ],
+    scala_deps = [
+        "@maven//:org_scalaz_scalaz_core",
     ],
     scalacopts = scalacopts,
     tags = ["maven_coordinates=com.daml:concurrent:__VERSION__"],
@@ -24,7 +28,6 @@ da_scala_library(
         "//visibility:public",
     ],
     deps = [
-        "@maven//:org_scalaz_scalaz_core_2_12",
         "@maven//:org_slf4j_slf4j_api",
     ],
 )
@@ -32,11 +35,13 @@ da_scala_library(
 da_scala_test(
     name = "test",
     srcs = glob(["src/test/scala/**/*.scala"]),
+    scala_deps = [
+        "@maven//:com_chuusai_shapeless",
+        "@maven//:org_scalaz_scalaz_core",
+    ],
     scalacopts = scalacopts,
     silent_annotations = True,
     deps = [
         ":concurrent",
-        "@maven//:com_chuusai_shapeless_2_12",
-        "@maven//:org_scalaz_scalaz_core_2_12",
     ],
 )
diff --git a/libs-scala/concurrent/src/main/scala/concurrent/ExecutionContextOf.scala b/libs-scala/concurrent/src/main/scala/concurrent/ExecutionContextOf.scala
index c4d829259916..f22552dcde44 100644
--- a/libs-scala/concurrent/src/main/scala/concurrent/ExecutionContextOf.scala
+++ b/libs-scala/concurrent/src/main/scala/concurrent/ExecutionContextOf.scala
@@ -3,7 +3,6 @@
 
 package com.daml.concurrent
 
-import scala.language.higherKinds
 import scala.{concurrent => sc}
 
 sealed abstract class ExecutionContextOf {
diff --git a/libs-scala/concurrent/src/main/scala/concurrent/FutureOf.scala b/libs-scala/concurrent/src/main/scala/concurrent/FutureOf.scala
index 89c1c77b10be..533fc6e4c4dc 100644
--- a/libs-scala/concurrent/src/main/scala/concurrent/FutureOf.scala
+++ b/libs-scala/concurrent/src/main/scala/concurrent/FutureOf.scala
@@ -3,7 +3,7 @@
 
 package com.daml.concurrent
 
-import scala.language.{higherKinds, implicitConversions}
+import scala.language.implicitConversions
 import scala.{concurrent => sc}
 import scala.util.Try
 
@@ -108,7 +108,7 @@ object FutureOf {
 
     def transform[B](s: A => B, f: Throwable => Throwable)(
         implicit ec: ExecutionContext[EC]): Future[EC, B] =
-      self.removeExecutionContext transform (s, f)
+      self.removeExecutionContext.transform(s, f)
 
     def foreach[U](f: A => U)(implicit ec: ExecutionContext[EC]): Unit =
       self.removeExecutionContext foreach f
diff --git a/libs-scala/concurrent/src/test/scala/concurrent/ExecutionContextSpec.scala b/libs-scala/concurrent/src/test/scala/concurrent/ExecutionContextSpec.scala
index 2761768a22c5..8cfa2071cd46 100644
--- a/libs-scala/concurrent/src/test/scala/concurrent/ExecutionContextSpec.scala
+++ b/libs-scala/concurrent/src/test/scala/concurrent/ExecutionContextSpec.scala
@@ -5,13 +5,11 @@ package com.daml.concurrent
 
 import scala.{concurrent => sc}
 
-import com.github.ghik.silencer.silent
 import org.scalatest.wordspec.AnyWordSpec
 import org.scalatest.matchers.should.Matchers
 import shapeless.test.illTyped
 
 @SuppressWarnings(Array("org.wartremover.warts.NonUnitStatements"))
-@silent("Unused import")
 class ExecutionContextSpec extends AnyWordSpec with Matchers {
   import ExecutionContextSpec._
 
@@ -76,7 +74,7 @@ class ExecutionContextSpec extends AnyWordSpec with Matchers {
   }
 
   "using intersections" should {
-    import TestImplicits.{Elephant, Cat, cryptozoology}
+    import TestImplicits.{Elephant, cryptozoology}
 
     "prefer the intersection" in {
       theEC[Elephant] should ===(cryptozoology)
diff --git a/libs-scala/contextualized-logging/BUILD.bazel b/libs-scala/contextualized-logging/BUILD.bazel
index 4d86494acdff..69beeee08a63 100644
--- a/libs-scala/contextualized-logging/BUILD.bazel
+++ b/libs-scala/contextualized-logging/BUILD.bazel
@@ -10,16 +10,23 @@ load(
 da_scala_library(
     name = "contextualized-logging",
     srcs = glob(["src/main/scala/**/*.scala"]),
+    scala_deps = [
+        "@maven//:com_typesafe_akka_akka_actor",
+        "@maven//:com_typesafe_akka_akka_stream",
+    ],
     scalacopts = ["-Xsource:2.13"],
     silent_annotations = True,
     tags = ["maven_coordinates=com.daml:contextualized-logging:__VERSION__"],
+    versioned_scala_deps = {
+        "2.12": [
+            "@maven//:org_scala_lang_modules_scala_collection_compat",
+        ],
+    },
     visibility = [
         "//visibility:public",
     ],
     deps = [
         "//libs-scala/grpc-utils",
-        "@maven//:com_typesafe_akka_akka_actor_2_12",
-        "@maven//:com_typesafe_akka_akka_stream_2_12",
         "@maven//:io_grpc_grpc_api",
         "@maven//:net_logstash_logback_logstash_logback_encoder",
         "@maven//:org_slf4j_slf4j_api",
@@ -29,19 +36,21 @@ da_scala_library(
 da_scala_test_suite(
     name = "contextualized-logging-tests",
     srcs = glob(["src/test/suite/**/*.scala"]),
+    scala_deps = [
+        "@maven//:com_chuusai_shapeless",
+        "@maven//:io_circe_circe_core",
+        "@maven//:io_circe_circe_generic",
+        "@maven//:io_circe_circe_parser",
+        "@maven//:org_mockito_mockito_scala",
+        "@maven//:org_typelevel_cats_core",
+        "@maven//:org_typelevel_cats_kernel",
+    ],
     deps = [
         ":contextualized-logging",
         "@maven//:ch_qos_logback_logback_classic",
         "@maven//:ch_qos_logback_logback_core",
-        "@maven//:com_chuusai_shapeless_2_12",
-        "@maven//:io_circe_circe_core_2_12",
-        "@maven//:io_circe_circe_generic_2_12",
-        "@maven//:io_circe_circe_parser_2_12",
         "@maven//:net_logstash_logback_logstash_logback_encoder",
         "@maven//:org_mockito_mockito_core",
-        "@maven//:org_mockito_mockito_scala_2_12",
         "@maven//:org_slf4j_slf4j_api",
-        "@maven//:org_typelevel_cats_core_2_12",
-        "@maven//:org_typelevel_cats_kernel_2_12",
     ],
 )
diff --git a/libs-scala/contextualized-logging/src/main/scala/com/digitalasset/logging/LoggingContext.scala b/libs-scala/contextualized-logging/src/main/scala/com/digitalasset/logging/LoggingContext.scala
index fa9dc9445012..6c4ec5dc021c 100644
--- a/libs-scala/contextualized-logging/src/main/scala/com/digitalasset/logging/LoggingContext.scala
+++ b/libs-scala/contextualized-logging/src/main/scala/com/digitalasset/logging/LoggingContext.scala
@@ -7,7 +7,7 @@ import net.logstash.logback.argument.StructuredArgument
 import net.logstash.logback.marker.MapEntriesAppendingMarker
 import org.slf4j.Marker
 
-import scala.collection.JavaConverters.mapAsJavaMapConverter
+import scala.jdk.CollectionConverters._
 
 object LoggingContext {
 
diff --git a/libs-scala/contextualized-logging/src/main/scala/com/digitalasset/logging/LoggingContextOf.scala b/libs-scala/contextualized-logging/src/main/scala/com/digitalasset/logging/LoggingContextOf.scala
index e0332136dde0..67159e67d0a5 100644
--- a/libs-scala/contextualized-logging/src/main/scala/com/digitalasset/logging/LoggingContextOf.scala
+++ b/libs-scala/contextualized-logging/src/main/scala/com/digitalasset/logging/LoggingContextOf.scala
@@ -5,7 +5,7 @@ package com.daml.logging
 
 import com.github.ghik.silencer.silent
 
-import scala.language.{higherKinds, implicitConversions}
+import scala.language.implicitConversions
 
 /** [[LoggingContext]] with a phantom type parameter representing what kind of
   * details are in it.  If a function that accepts a LoggingContext is supposed
diff --git a/libs-scala/contextualized-logging/src/test/suite/scala/com/digitalasset/logging/ContextualizedLoggerIT.scala b/libs-scala/contextualized-logging/src/test/suite/scala/com/digitalasset/logging/ContextualizedLoggerIT.scala
index e1ef037b2879..01e35fe40608 100644
--- a/libs-scala/contextualized-logging/src/test/suite/scala/com/digitalasset/logging/ContextualizedLoggerIT.scala
+++ b/libs-scala/contextualized-logging/src/test/suite/scala/com/digitalasset/logging/ContextualizedLoggerIT.scala
@@ -96,7 +96,7 @@ object ContextualizedLoggerIT {
     val contextualizedLogger = ContextualizedLogger.createFor(logger)
     t(contextualizedLogger)
     output.close()
-    output.toString.split(System.lineSeparator())
+    output.toString.split(System.lineSeparator()).toIndexedSeq
   }
 
   private[this] def setupLogger(encoder: Encoder[ILoggingEvent]): (Logger, OutputStream) = {
diff --git a/libs-scala/flyway-testing/BUILD.bazel b/libs-scala/flyway-testing/BUILD.bazel
index 519a9ac8e374..b319efd56b97 100644
--- a/libs-scala/flyway-testing/BUILD.bazel
+++ b/libs-scala/flyway-testing/BUILD.bazel
@@ -6,11 +6,16 @@ load("//bazel_tools:scala.bzl", "da_scala_library")
 da_scala_library(
     name = "flyway-testing",
     srcs = glob(["src/main/scala/**/*.scala"]),
+    scala_deps = [
+        "@maven//:org_scalactic_scalactic",
+        "@maven//:org_scalatest_scalatest",
+    ],
     tags = ["maven_coordinates=com.daml:flyway-testing:__VERSION__"],
+    versioned_scala_deps = {
+        "2.12": ["@maven//:org_scala_lang_modules_scala_collection_compat"],
+    },
     visibility = ["//visibility:public"],
     deps = [
         "@maven//:org_flywaydb_flyway_core",
-        "@maven//:org_scalactic_scalactic_2_12",
-        "@maven//:org_scalatest_scalatest_2_12",
     ],
 )
diff --git a/libs-scala/flyway-testing/src/main/scala/flyway/AbstractImmutableMigrationsSpec.scala b/libs-scala/flyway-testing/src/main/scala/flyway/AbstractImmutableMigrationsSpec.scala
index 49df3344c0ca..f15ed2dabde6 100644
--- a/libs-scala/flyway-testing/src/main/scala/flyway/AbstractImmutableMigrationsSpec.scala
+++ b/libs-scala/flyway-testing/src/main/scala/flyway/AbstractImmutableMigrationsSpec.scala
@@ -16,7 +16,7 @@ import org.flywaydb.core.internal.scanner.{LocationScannerCache, ResourceNameCac
 import org.scalatest.matchers.should.Matchers._
 import org.scalatest.wordspec.AnyWordSpec
 
-import scala.collection.JavaConverters._
+import scala.jdk.CollectionConverters._
 
 abstract class AbstractImmutableMigrationsSpec extends AnyWordSpec {
   protected def migrationsResourcePath: String
diff --git a/libs-scala/gatling-utils/BUILD.bazel b/libs-scala/gatling-utils/BUILD.bazel
index d0ec5568e136..782abc69e972 100644
--- a/libs-scala/gatling-utils/BUILD.bazel
+++ b/libs-scala/gatling-utils/BUILD.bazel
@@ -7,6 +7,8 @@ load(
     "da_scala_test",
     "lf_scalacopts",
 )
+load("@scala_version//:index.bzl", "scala_version_suffix")
+load("//bazel_tools:scala.bzl", "silencer_plugin")
 
 scalacopts = lf_scalacopts + [
     "-P:wartremover:traverser:org.wartremover.warts.NonUnitStatements",
@@ -16,9 +18,18 @@ da_scala_library(
     name = "gatling-utils",
     srcs = glob(["src/main/scala/**/*.scala"]),
     plugins = [
-        "@maven//:org_typelevel_kind_projector_2_12_12",
+        "@maven//:org_typelevel_kind_projector_{}".format(scala_version_suffix),
+        silencer_plugin,
+    ],
+    scala_deps = [
+        "@maven//:com_typesafe_akka_akka_actor",
+        "@maven//:org_scalaz_scalaz_core",
+        "@maven//:com_typesafe_scala_logging_scala_logging",
+        "@maven//:org_scala_lang_modules_scala_collection_compat",
+    ],
+    scalacopts = scalacopts + [
+        "-P:silencer:lineContentFilters=import scala.collection.compat",
     ],
-    scalacopts = scalacopts,
     tags = ["maven_coordinates=com.daml:gatling-utils:__VERSION__"],
     visibility = ["//visibility:public"],
     runtime_deps = [
@@ -26,11 +37,8 @@ da_scala_library(
     ],
     deps = [
         "//libs-scala/scala-utils",
-        "@maven//:com_typesafe_akka_akka_actor_2_12",
-        "@maven//:com_typesafe_scala_logging_scala_logging_2_12",
         "@maven//:io_gatling_gatling_app",
         "@maven//:io_gatling_gatling_core",
-        "@maven//:org_scalaz_scalaz_core_2_12",
         "@maven//:org_slf4j_slf4j_api",
     ],
 )
@@ -48,17 +56,19 @@ da_scala_test(
         ":test-simulation-logs",
     ],
     plugins = [
-        "@maven//:org_typelevel_kind_projector_2_12_12",
+        "@maven//:org_typelevel_kind_projector_{}".format(scala_version_suffix),
+    ],
+    scala_deps = [
+        "@maven//:org_scalacheck_scalacheck",
+        "@maven//:org_scalatest_scalatest",
+        "@maven//:org_scalatestplus_scalacheck_1_14",
+        "@maven//:org_scalaz_scalaz_core",
+        "@maven//:org_scalaz_scalaz_scalacheck_binding",
     ],
     scalacopts = scalacopts,
     deps = [
         ":gatling-utils",
         "//bazel_tools/runfiles:scala_runfiles",
         "//libs-scala/scalatest-utils",
-        "@maven//:org_scalacheck_scalacheck_2_12",
-        "@maven//:org_scalatest_scalatest_2_12",
-        "@maven//:org_scalatestplus_scalacheck_1_14_2_12",
-        "@maven//:org_scalaz_scalaz_core_2_12",
-        "@maven//:org_scalaz_scalaz_scalacheck_binding_2_12",
     ],
 )
diff --git a/libs-scala/gatling-utils/src/main/scala/com/daml/gatling/stats/SimulationLog.scala b/libs-scala/gatling-utils/src/main/scala/com/daml/gatling/stats/SimulationLog.scala
index 4088c7f975f3..161d0b8b7d46 100644
--- a/libs-scala/gatling-utils/src/main/scala/com/daml/gatling/stats/SimulationLog.scala
+++ b/libs-scala/gatling-utils/src/main/scala/com/daml/gatling/stats/SimulationLog.scala
@@ -11,6 +11,7 @@ import java.io.File
 import scalaz._
 import Scalaz._
 
+import scala.collection.compat._
 import scala.collection.immutable.ListMap
 
 import com.daml.gatling.stats.util.NonEmptySyntax._
@@ -241,7 +242,7 @@ object SimulationLog {
       simulation <- processSimulation(scenarios)(rowsByType.getOrElse("RUN", List.empty))
     } yield simulation
 
-  private def groupRowsByType(fileContent: String) =
+  private def groupRowsByType(fileContent: String): String \/ Map[String, List[Seq[String]]] =
     \/.fromTryCatchNonFatal {
       fileContent
         .split('\n')
@@ -249,7 +250,9 @@ object SimulationLog {
         .collect { case rowType +: fields => rowType -> fields }
         .toList
         .groupBy(_._1)
+        .view
         .mapValues(_.map(_._2))
+        .toMap
     }.leftMap(_.getMessage)
 
   def processScenarios(requestsByUser: Map[Int, Seq[RequestStats]])(
@@ -260,10 +263,12 @@ object SimulationLog {
         .collect { case Seq(label, userId, "START", _*) => userId -> label }
         .foldRight(Map.empty[String, ScenarioStats]) {
           case ((userId, label), result) =>
-            val requestsByType = requestsByUser
+            val requestsByType: Map[String, RequestTypeStats] = requestsByUser
               .getOrElse(userId.toInt, Seq.empty)
               .groupBy(_.requestLabel)
+              .view
               .mapValues(RequestTypeStats.fromRequestStats)
+              .toMap
             val s = result.getOrElse(label, ScenarioStats(label))
             result + (label -> s.copy(
               maxUsers = s.maxUsers + 1,
diff --git a/libs-scala/gatling-utils/src/test/scala/com/daml/gatling/stats/SimulationLogSpec.scala b/libs-scala/gatling-utils/src/test/scala/com/daml/gatling/stats/SimulationLogSpec.scala
index 4e5246c9308e..7e7abc466f20 100644
--- a/libs-scala/gatling-utils/src/test/scala/com/daml/gatling/stats/SimulationLogSpec.scala
+++ b/libs-scala/gatling-utils/src/test/scala/com/daml/gatling/stats/SimulationLogSpec.scala
@@ -26,19 +26,19 @@ class SimulationLogSpec extends AnyFlatSpec with Matchers with TypeCheckedTriple
     SimulationLog.fromFile(requiredResource(s"$simulationLog/$fileName.txt"))
 
   it should "fail if file does not exist" in {
-    SimulationLog.fromFile(new File("DOES-NOT-EXIST-OgUzdJsvKHc9TtfNiLXA")) shouldBe 'left
+    SimulationLog.fromFile(new File("DOES-NOT-EXIST-OgUzdJsvKHc9TtfNiLXA")) shouldBe Symbol("left")
   }
 
   it should "fail if no RUN entry" in {
-    resultFor("no-run") shouldBe 'left
+    resultFor("no-run") shouldBe Symbol("left")
   }
 
   it should "fail if no USER entry" in {
-    resultFor("no-user") shouldBe 'left
+    resultFor("no-user") shouldBe Symbol("left")
   }
 
   it should "fail if multiple RUN entries" in {
-    resultFor("multiple-run") shouldBe 'left
+    resultFor("multiple-run") shouldBe Symbol("left")
   }
 
   it should "return correct result for minimal log" in {
diff --git a/libs-scala/postgresql-testing/BUILD.bazel b/libs-scala/postgresql-testing/BUILD.bazel
index b92319177a96..26d03c3ed975 100644
--- a/libs-scala/postgresql-testing/BUILD.bazel
+++ b/libs-scala/postgresql-testing/BUILD.bazel
@@ -13,6 +13,15 @@ da_scala_library(
     data = [
         "@postgresql_dev_env//:all",
     ],
+    scala_deps = [
+        "@maven//:org_scalactic_scalactic",
+        "@maven//:org_scalatest_scalatest",
+    ],
+    versioned_scala_deps = {
+        "2.12": [
+            "@maven//:org_scala_lang_modules_scala_collection_compat",
+        ],
+    },
     visibility = [
         "//visibility:public",
     ],
@@ -22,7 +31,5 @@ da_scala_library(
         "//libs-scala/ports",
         "//libs-scala/resources",
         "@maven//:commons_io_commons_io",
-        "@maven//:org_scalactic_scalactic_2_12",
-        "@maven//:org_scalatest_scalatest_2_12",
     ],
 )
diff --git a/libs-scala/postgresql-testing/src/main/scala/com/digitalasset/testing/postgresql/PostgresAround.scala b/libs-scala/postgresql-testing/src/main/scala/com/digitalasset/testing/postgresql/PostgresAround.scala
index ea9b81f867c0..dcf5bbbbd77f 100644
--- a/libs-scala/postgresql-testing/src/main/scala/com/digitalasset/testing/postgresql/PostgresAround.scala
+++ b/libs-scala/postgresql-testing/src/main/scala/com/digitalasset/testing/postgresql/PostgresAround.scala
@@ -15,7 +15,7 @@ import com.daml.testing.postgresql.PostgresAround._
 import org.apache.commons.io.{FileUtils, IOUtils}
 import org.slf4j.LoggerFactory
 
-import scala.collection.JavaConverters.asScalaBufferConverter
+import scala.jdk.CollectionConverters._
 import scala.util.Try
 import scala.util.control.NonFatal
 
@@ -149,7 +149,7 @@ trait PostgresAround {
     "UNICODE",
     "-A",
     "trust",
-    dataDir.toString.replaceAllLiterally("\\", "/"),
+    dataDir.toString.replace("\\", "/"),
   )
 
   private def createConfigFile(configPath: Path): Unit = {
@@ -232,7 +232,7 @@ trait PostgresAround {
   }
 
   private def readLogs(): Seq[String] =
-    Try(paths.map(paths => Files.readAllLines(paths.logFile).asScala).getOrElse(Seq.empty))
+    Try(paths.map(paths => Files.readAllLines(paths.logFile).asScala.toSeq).getOrElse(Seq.empty))
       .getOrElse(Seq.empty)
 
   private def deleteRecursively(tempDir: Path): Unit =
diff --git a/libs-scala/resources-akka/BUILD.bazel b/libs-scala/resources-akka/BUILD.bazel
index 2dc6355972f2..795ffa49fa1e 100644
--- a/libs-scala/resources-akka/BUILD.bazel
+++ b/libs-scala/resources-akka/BUILD.bazel
@@ -6,25 +6,29 @@ load("//bazel_tools:scala.bzl", "da_scala_library", "da_scala_test_suite")
 da_scala_library(
     name = "resources-akka",
     srcs = glob(["src/main/scala/**/*.scala"]),
+    scala_deps = [
+        "@maven//:com_typesafe_akka_akka_actor",
+        "@maven//:com_typesafe_akka_akka_stream",
+    ],
     tags = ["maven_coordinates=com.daml:resources-akka:__VERSION__"],
     visibility = [
         "//visibility:public",
     ],
     deps = [
         "//libs-scala/resources",
-        "@maven//:com_typesafe_akka_akka_actor_2_12",
-        "@maven//:com_typesafe_akka_akka_stream_2_12",
     ],
 )
 
 da_scala_test_suite(
     name = "resources-akka-tests",
     srcs = glob(["src/test/suite/**/*.scala"]),
+    scala_deps = [
+        "@maven//:com_typesafe_akka_akka_actor",
+        "@maven//:com_typesafe_akka_akka_stream",
+    ],
     deps = [
         ":resources-akka",
         "//libs-scala/resources",
         "//libs-scala/resources:resources-test-lib",
-        "@maven//:com_typesafe_akka_akka_actor_2_12",
-        "@maven//:com_typesafe_akka_akka_stream_2_12",
     ],
 )
diff --git a/libs-scala/resources/BUILD.bazel b/libs-scala/resources/BUILD.bazel
index 6651652cd6a9..b270f6e8e7c7 100644
--- a/libs-scala/resources/BUILD.bazel
+++ b/libs-scala/resources/BUILD.bazel
@@ -2,17 +2,21 @@
 # SPDX-License-Identifier: Apache-2.0
 
 load("//bazel_tools:scala.bzl", "da_scala_library", "da_scala_test_suite")
+load("@scala_version//:index.bzl", "scala_major_version")
 
 da_scala_library(
     name = "resources",
-    srcs = glob(["src/main/scala/**/*.scala"]),
+    srcs = glob(["src/main/scala/**/*.scala"]) + glob(["src/main/{}/**/*.scala".format(scala_major_version)]),
+    scala_deps = [
+        "@maven//:org_scala_lang_modules_scala_java8_compat",
+        "@maven//:org_scala_lang_modules_scala_collection_compat",
+    ],
     tags = ["maven_coordinates=com.daml:resources:__VERSION__"],
     visibility = [
         "//visibility:public",
     ],
     deps = [
         "//libs-scala/contextualized-logging",
-        "@maven//:org_scala_lang_modules_scala_java8_compat_2_12",
     ],
 )
 
@@ -30,6 +34,9 @@ da_scala_library(
 da_scala_test_suite(
     name = "resources-tests",
     srcs = glob(["src/test/suite/**/*.scala"]),
+    scala_deps = [
+        "@maven//:org_scala_lang_modules_scala_collection_compat",
+    ],
     silent_annotations = True,
     deps = [
         ":resources",
diff --git a/libs-scala/resources/src/main/2.12/com/daml/resources/UnitCanBuildFrom.scala b/libs-scala/resources/src/main/2.12/com/daml/resources/UnitCanBuildFrom.scala
new file mode 100644
index 000000000000..d0a911e3dbb2
--- /dev/null
+++ b/libs-scala/resources/src/main/2.12/com/daml/resources/UnitCanBuildFrom.scala
@@ -0,0 +1,20 @@
+// Copyright (c) 2020 Digital Asset (Switzerland) GmbH and/or its affiliates. All rights reserved.
+// SPDX-License-Identifier: Apache-2.0
+
+package com.daml.resources
+
+import scala.collection.generic.CanBuildFrom
+import scala.collection.mutable
+
+private[resources] final class UnitCanBuildFrom[T, C[_]] extends CanBuildFrom[C[T], T, Unit] {
+  override def apply(): mutable.Builder[T, Unit] = UnitBuilder
+  override def apply(from: C[T]): mutable.Builder[T, Unit] = apply()
+}
+
+private[resources] object UnitBuilder extends mutable.Builder[Any, Unit] {
+  override def +=(elem: Any): this.type = this
+
+  override def clear(): Unit = ()
+
+  override def result(): Unit = ()
+}
diff --git a/libs-scala/resources/src/main/2.13/com/daml/resources/UnitCanBuildFrom.scala b/libs-scala/resources/src/main/2.13/com/daml/resources/UnitCanBuildFrom.scala
new file mode 100644
index 000000000000..8e5639d233e5
--- /dev/null
+++ b/libs-scala/resources/src/main/2.13/com/daml/resources/UnitCanBuildFrom.scala
@@ -0,0 +1,20 @@
+// Copyright (c) 2020 Digital Asset (Switzerland) GmbH and/or its affiliates. All rights reserved.
+// SPDX-License-Identifier: Apache-2.0
+
+package com.daml.resources
+
+import scala.collection.compat._
+import scala.collection.mutable
+
+private[resources] final class UnitCanBuildFrom[T, C[_]] extends Factory[T, Unit] {
+  override def fromSpecific(it: IterableOnce[T]) = ()
+  override def newBuilder: mutable.Builder[T, Unit] = UnitBuilder
+}
+
+private[resources] object UnitBuilder extends mutable.Builder[Any, Unit] {
+  override def addOne(elem: Any): this.type = this
+
+  override def clear(): Unit = ()
+
+  override def result(): Unit = ()
+}
diff --git a/libs-scala/resources/src/main/scala/com/digitalasset/resources/ResourceFactories.scala b/libs-scala/resources/src/main/scala/com/digitalasset/resources/ResourceFactories.scala
index 26fd30661a7f..aec0c6d20960 100644
--- a/libs-scala/resources/src/main/scala/com/digitalasset/resources/ResourceFactories.scala
+++ b/libs-scala/resources/src/main/scala/com/digitalasset/resources/ResourceFactories.scala
@@ -7,15 +7,12 @@ import java.util.concurrent.atomic.AtomicBoolean
 
 import com.daml.resources.HasExecutionContext.executionContext
 
-import scala.collection.generic.CanBuildFrom
-import scala.collection.mutable
+import scala.collection.compat._
 import scala.concurrent.{Future, Promise}
 import scala.util.{Failure, Success}
 
 final class ResourceFactories[Context: HasExecutionContext] {
 
-  import scala.language.higherKinds
-
   private type R[+T] = Resource[Context, T]
 
   /**
@@ -101,12 +98,12 @@ final class ResourceFactories[Context: HasExecutionContext] {
     * @tparam U The return type.
     * @return A [[Resource]] with a sequence of the values of the sequenced [[Resource]]s as its underlying value.
     */
-  def sequence[T, C[X] <: Traversable[X], U](seq: C[R[T]])(
-      implicit bf: CanBuildFrom[C[R[T]], T, U],
+  def sequence[T, C[X] <: Iterable[X], U](seq: C[R[T]])(
+      implicit bf: Factory[T, U],
       context: Context,
   ): R[U] = new R[U] {
     private val resource = seq
-      .foldLeft(successful(bf()))((builderResource, elementResource) =>
+      .foldLeft(successful(bf.newBuilder))((builderResource, elementResource) =>
         for {
           builder <- builderResource // Consider the builder in the accumulator resource
           element <- elementResource // Consider the value in the actual resource element
@@ -129,23 +126,9 @@ final class ResourceFactories[Context: HasExecutionContext] {
     * @tparam C The [[Traversable]] actual type.
     * @return A [[Resource]] sequencing the [[Resource]]s and no underlying value.
     */
-  def sequenceIgnoringValues[T, C[X] <: Traversable[X]](seq: C[R[T]])(
+  def sequenceIgnoringValues[T, C[X] <: Iterable[X]](seq: C[R[T]])(
       implicit context: Context
   ): R[Unit] =
-    sequence(seq)(new UnitCanBuildFrom, context)
-
-  final class UnitCanBuildFrom[T, C[X] <: Traversable[X]] extends CanBuildFrom[C[R[T]], T, Unit] {
-    override def apply(from: C[R[T]]): mutable.Builder[T, Unit] = apply()
-
-    override def apply(): mutable.Builder[T, Unit] = UnitBuilder
-  }
-
-  object UnitBuilder extends mutable.Builder[Any, Unit] {
-    override def +=(elem: Any): this.type = this
-
-    override def clear(): Unit = ()
-
-    override def result(): Unit = ()
-  }
+    sequence(seq)(new UnitCanBuildFrom[T, Nothing], context)
 
 }
diff --git a/libs-scala/scala-utils/BUILD.bazel b/libs-scala/scala-utils/BUILD.bazel
index 5f306d34e60e..7da5b3020180 100644
--- a/libs-scala/scala-utils/BUILD.bazel
+++ b/libs-scala/scala-utils/BUILD.bazel
@@ -27,10 +27,12 @@ da_scala_library(
 da_scala_test(
     name = "test",
     srcs = glob(["src/test/scala/**/*.scala"]),
+    scala_deps = [
+        "@maven//:org_scalaz_scalaz_core",
+    ],
     scalacopts = scalacopts,
     deps = [
         ":scala-utils",
         "//libs-scala/scalatest-utils",
-        "@maven//:org_scalaz_scalaz_core_2_12",
     ],
 )
diff --git a/libs-scala/scala-utils/src/main/scala/com/daml/scalautil/Statement.scala b/libs-scala/scala-utils/src/main/scala/com/daml/scalautil/Statement.scala
index d7f539ba0b4a..9f4443f977c7 100644
--- a/libs-scala/scala-utils/src/main/scala/com/daml/scalautil/Statement.scala
+++ b/libs-scala/scala-utils/src/main/scala/com/daml/scalautil/Statement.scala
@@ -12,7 +12,7 @@ object Statement {
     * @tparam A return type of the expression that gets discarded.
     */
   @specialized def discard[A](evaluateForSideEffectOnly: A): Unit = {
-    val _: A = evaluateForSideEffectOnly
+    val _ = evaluateForSideEffectOnly
     () //Return unit to prevent warning due to discarding value
   }
 }
diff --git a/libs-scala/scalatest-utils/BUILD.bazel b/libs-scala/scalatest-utils/BUILD.bazel
index c364bad78e13..59f927c6a655 100644
--- a/libs-scala/scalatest-utils/BUILD.bazel
+++ b/libs-scala/scalatest-utils/BUILD.bazel
@@ -7,32 +7,35 @@ load(
     "da_scala_test",
     "lf_scalacopts",
 )
+load("@scala_version//:index.bzl", "scala_version_suffix")
 
 da_scala_library(
     name = "scalatest-utils",
     srcs = glob(["src/main/**/*.scala"]),
     plugins = [
-        "@maven//:org_typelevel_kind_projector_2_12_12",
+        "@maven//:org_typelevel_kind_projector_{}".format(scala_version_suffix),
+    ],
+    scala_deps = [
+        "@maven//:org_scalacheck_scalacheck",
+        "@maven//:org_scalactic_scalactic",
+        "@maven//:org_scalatest_scalatest",
+        "@maven//:org_scalatestplus_scalacheck_1_14",
+        "@maven//:org_scalaz_scalaz_core",
     ],
     scalacopts = lf_scalacopts,
     tags = ["maven_coordinates=com.daml:scalatest-utils:__VERSION__"],
     visibility = ["//visibility:public"],
-    deps = [
-        "@maven//:org_scalacheck_scalacheck_2_12",
-        "@maven//:org_scalactic_scalactic_2_12",
-        "@maven//:org_scalatest_scalatest_2_12",
-        "@maven//:org_scalatestplus_scalacheck_1_14_2_12",
-        "@maven//:org_scalaz_scalaz_core_2_12",
-    ],
 )
 
 da_scala_test(
     name = "test",
     size = "small",
     srcs = glob(["src/test/**/*.scala"]),
+    scala_deps = [
+        "@maven//:org_scalaz_scalaz_core",
+    ],
     scalacopts = lf_scalacopts,
     deps = [
         ":scalatest-utils",
-        "@maven//:org_scalaz_scalaz_core_2_12",
     ],
 )
diff --git a/libs-scala/scalatest-utils/src/main/scala/scalatest/AsyncForAll.scala b/libs-scala/scalatest-utils/src/main/scala/scalatest/AsyncForAll.scala
index aa9822acfd3d..d4b6f5900865 100644
--- a/libs-scala/scalatest-utils/src/main/scala/scalatest/AsyncForAll.scala
+++ b/libs-scala/scalatest-utils/src/main/scala/scalatest/AsyncForAll.scala
@@ -23,7 +23,7 @@ trait AsyncForAll {
       .getOrElse(sys error "random Gen failed")
 
     implicit val assertionMonoid: Monoid[Future[Assertion]] =
-      Monoid liftMonoid (Applicative[Future], Monoid instance ((_, result) => result, succeed))
+      Monoid.liftMonoid(Applicative[Future], Monoid.instance((_, result) => result, succeed))
     runs foldMap { a =>
       f(a) recoverWith {
         case ae: TestFailedException =>
diff --git a/libs-scala/scalatest-utils/src/main/scala/scalatest/Equalz.scala b/libs-scala/scalatest-utils/src/main/scala/scalatest/Equalz.scala
index 88911b2e46b1..b43362edbe4d 100644
--- a/libs-scala/scalatest-utils/src/main/scala/scalatest/Equalz.scala
+++ b/libs-scala/scalatest-utils/src/main/scala/scalatest/Equalz.scala
@@ -6,7 +6,6 @@ package com.daml.scalatest
 import org.scalatest.matchers.dsl.{MatcherFactory1}
 import org.scalatest.matchers.{MatchResult, Matcher}
 import org.scalatest.matchers.should.Matchers
-import scala.language.higherKinds
 import scalaz.Equal
 
 /** Provides the `equalz` [[Matcher]].
diff --git a/libs-scala/timer-utils/src/main/scala/com/digitalasset/timer/PromiseTask.scala b/libs-scala/timer-utils/src/main/scala/com/digitalasset/timer/PromiseTask.scala
index e2367274c77a..0ba1e06193e9 100644
--- a/libs-scala/timer-utils/src/main/scala/com/digitalasset/timer/PromiseTask.scala
+++ b/libs-scala/timer-utils/src/main/scala/com/digitalasset/timer/PromiseTask.scala
@@ -11,10 +11,10 @@ import scala.util.control.NonFatal
 
 private class PromiseTask[A](value: => Future[A]) extends TimerTask with Promise[A] {
 
-  private val p = Promise[A]
+  private val p = Promise[A]()
 
   override def run(): Unit = {
-    p.tryCompleteWith {
+    p.completeWith {
       try value
       catch { case NonFatal(t) => Future.failed(t) }
     }
diff --git a/scala-protoc-plugins/scalapb/BUILD.bazel b/scala-protoc-plugins/scalapb/BUILD.bazel
index 734bb27bb7e7..f2832aa30a8a 100644
--- a/scala-protoc-plugins/scalapb/BUILD.bazel
+++ b/scala-protoc-plugins/scalapb/BUILD.bazel
@@ -7,11 +7,13 @@ da_scala_binary(
     name = "compiler_plugin",
     srcs = glob(["*.scala"]),
     main_class = "com.daml.protoc.plugins.scalapb.ScalaPbCompilerPlugin",
+    scala_deps = [
+        "@maven//:com_thesamet_scalapb_compilerplugin",
+        "@maven//:com_thesamet_scalapb_protoc_bridge",
+    ],
     visibility = ["//visibility:public"],
     deps = [
         "@maven//:com_google_protobuf_protobuf_java",
-        "@maven//:com_thesamet_scalapb_compilerplugin_2_12",
-        "@maven//:com_thesamet_scalapb_protoc_bridge_2_12",
     ],
 )