diff --git a/lib/tsserver.js b/lib/tsserver.js
index a7e0b1aa9ff52..382e1e2937fd0 100644
--- a/lib/tsserver.js
+++ b/lib/tsserver.js
@@ -164760,11 +164760,11 @@ function provideInlayHints(context) {
   function isSignatureSupportingReturnAnnotation(node) {
     return isArrowFunction(node) || isFunctionExpression(node) || isFunctionDeclaration(node) || isMethodDeclaration(node) || isGetAccessorDeclaration(node);
   }
-  function addParameterHints(text, parameter, position, isFirstVariadicArgument, sourceFile) {
+  function addParameterHints(text, parameter, position, isFirstVariadicArgument) {
     let hintText = `${isFirstVariadicArgument ? "..." : ""}${text}`;
     let displayParts;
     if (shouldUseInteractiveInlayHints(preferences)) {
-      displayParts = [getNodeDisplayPart(hintText, parameter, sourceFile), { text: ":" }];
+      displayParts = [getNodeDisplayPart(hintText, parameter), { text: ":" }];
       hintText = "";
     } else {
       hintText += ":";
@@ -164837,7 +164837,6 @@ function provideInlayHints(context) {
       return;
     }
     let signatureParamPos = 0;
-    const sourceFile = shouldUseInteractiveInlayHints(preferences) ? expr.getSourceFile() : void 0;
     for (const originalArg of args) {
       const arg = skipParentheses(originalArg);
       if (shouldShowLiteralParameterNameHintsOnly(preferences) && !isHintableLiteral(arg)) {
@@ -164870,7 +164869,7 @@ function provideInlayHints(context) {
         if (leadingCommentsContainsParameterName(arg, name)) {
           continue;
         }
-        addParameterHints(name, parameter, originalArg.getStart(), isFirstVariadicArgument, sourceFile);
+        addParameterHints(name, parameter, originalArg.getStart(), isFirstVariadicArgument);
       }
     }
   }
@@ -165006,7 +165005,8 @@ function provideInlayHints(context) {
     }
     return true;
   }
-  function getNodeDisplayPart(text, node, sourceFile) {
+  function getNodeDisplayPart(text, node) {
+    const sourceFile = node.getSourceFile();
     return {
       text,
       span: createTextSpanFromNode(node, sourceFile),
@@ -183666,14 +183666,22 @@ Project '${project.projectName}' (${ProjectKind[project.projectKind]}) ${counter
       return {
         ...hint,
         position: scriptInfo.positionToLineOffset(position),
-        displayParts: displayParts == null ? void 0 : displayParts.map(({ text, span, file: file2 }) => ({
-          text,
-          span: span && {
-            start: scriptInfo.positionToLineOffset(span.start),
-            end: scriptInfo.positionToLineOffset(span.start + span.length),
-            file: file2
+        displayParts: displayParts == null ? void 0 : displayParts.map(({ text, span, file: file2 }) => {
+          if (span) {
+            Debug.assertIsDefined(file2, "Target file should be defined together with its span.");
+            const scriptInfo2 = this.projectService.getScriptInfo(file2);
+            return {
+              text,
+              span: {
+                start: scriptInfo2.positionToLineOffset(span.start),
+                end: scriptInfo2.positionToLineOffset(span.start + span.length),
+                file: file2
+              }
+            };
+          } else {
+            return { text };
           }
-        }))
+        })
       };
     });
   }
diff --git a/lib/tsserverlibrary.js b/lib/tsserverlibrary.js
index 52fc05e1a55c0..d53fe81a33a8d 100644
--- a/lib/tsserverlibrary.js
+++ b/lib/tsserverlibrary.js
@@ -164108,11 +164108,11 @@ ${newComment.split("\n").map((c) => ` * ${c}`).join("\n")}
     function isSignatureSupportingReturnAnnotation(node) {
       return isArrowFunction(node) || isFunctionExpression(node) || isFunctionDeclaration(node) || isMethodDeclaration(node) || isGetAccessorDeclaration(node);
     }
-    function addParameterHints(text, parameter, position, isFirstVariadicArgument, sourceFile) {
+    function addParameterHints(text, parameter, position, isFirstVariadicArgument) {
       let hintText = `${isFirstVariadicArgument ? "..." : ""}${text}`;
       let displayParts;
       if (shouldUseInteractiveInlayHints(preferences)) {
-        displayParts = [getNodeDisplayPart(hintText, parameter, sourceFile), { text: ":" }];
+        displayParts = [getNodeDisplayPart(hintText, parameter), { text: ":" }];
         hintText = "";
       } else {
         hintText += ":";
@@ -164185,7 +164185,6 @@ ${newComment.split("\n").map((c) => ` * ${c}`).join("\n")}
         return;
       }
       let signatureParamPos = 0;
-      const sourceFile = shouldUseInteractiveInlayHints(preferences) ? expr.getSourceFile() : void 0;
       for (const originalArg of args) {
         const arg = skipParentheses(originalArg);
         if (shouldShowLiteralParameterNameHintsOnly(preferences) && !isHintableLiteral(arg)) {
@@ -164218,7 +164217,7 @@ ${newComment.split("\n").map((c) => ` * ${c}`).join("\n")}
           if (leadingCommentsContainsParameterName(arg, name)) {
             continue;
           }
-          addParameterHints(name, parameter, originalArg.getStart(), isFirstVariadicArgument, sourceFile);
+          addParameterHints(name, parameter, originalArg.getStart(), isFirstVariadicArgument);
         }
       }
     }
@@ -164354,7 +164353,8 @@ ${newComment.split("\n").map((c) => ` * ${c}`).join("\n")}
       }
       return true;
     }
-    function getNodeDisplayPart(text, node, sourceFile) {
+    function getNodeDisplayPart(text, node) {
+      const sourceFile = node.getSourceFile();
       return {
         text,
         span: createTextSpanFromNode(node, sourceFile),
@@ -181073,14 +181073,22 @@ Project '${project.projectName}' (${ProjectKind[project.projectKind]}) ${counter
             return {
               ...hint,
               position: scriptInfo.positionToLineOffset(position),
-              displayParts: displayParts == null ? void 0 : displayParts.map(({ text, span, file: file2 }) => ({
-                text,
-                span: span && {
-                  start: scriptInfo.positionToLineOffset(span.start),
-                  end: scriptInfo.positionToLineOffset(span.start + span.length),
-                  file: file2
+              displayParts: displayParts == null ? void 0 : displayParts.map(({ text, span, file: file2 }) => {
+                if (span) {
+                  Debug.assertIsDefined(file2, "Target file should be defined together with its span.");
+                  const scriptInfo2 = this.projectService.getScriptInfo(file2);
+                  return {
+                    text,
+                    span: {
+                      start: scriptInfo2.positionToLineOffset(span.start),
+                      end: scriptInfo2.positionToLineOffset(span.start + span.length),
+                      file: file2
+                    }
+                  };
+                } else {
+                  return { text };
                 }
-              }))
+              })
             };
           });
         }
diff --git a/lib/typescript.js b/lib/typescript.js
index 52af03190f3d4..4d0ee15506636 100644
--- a/lib/typescript.js
+++ b/lib/typescript.js
@@ -164123,11 +164123,11 @@ ${newComment.split("\n").map((c) => ` * ${c}`).join("\n")}
     function isSignatureSupportingReturnAnnotation(node) {
       return isArrowFunction(node) || isFunctionExpression(node) || isFunctionDeclaration(node) || isMethodDeclaration(node) || isGetAccessorDeclaration(node);
     }
-    function addParameterHints(text, parameter, position, isFirstVariadicArgument, sourceFile) {
+    function addParameterHints(text, parameter, position, isFirstVariadicArgument) {
       let hintText = `${isFirstVariadicArgument ? "..." : ""}${text}`;
       let displayParts;
       if (shouldUseInteractiveInlayHints(preferences)) {
-        displayParts = [getNodeDisplayPart(hintText, parameter, sourceFile), { text: ":" }];
+        displayParts = [getNodeDisplayPart(hintText, parameter), { text: ":" }];
         hintText = "";
       } else {
         hintText += ":";
@@ -164200,7 +164200,6 @@ ${newComment.split("\n").map((c) => ` * ${c}`).join("\n")}
         return;
       }
       let signatureParamPos = 0;
-      const sourceFile = shouldUseInteractiveInlayHints(preferences) ? expr.getSourceFile() : void 0;
       for (const originalArg of args) {
         const arg = skipParentheses(originalArg);
         if (shouldShowLiteralParameterNameHintsOnly(preferences) && !isHintableLiteral(arg)) {
@@ -164233,7 +164232,7 @@ ${newComment.split("\n").map((c) => ` * ${c}`).join("\n")}
           if (leadingCommentsContainsParameterName(arg, name)) {
             continue;
           }
-          addParameterHints(name, parameter, originalArg.getStart(), isFirstVariadicArgument, sourceFile);
+          addParameterHints(name, parameter, originalArg.getStart(), isFirstVariadicArgument);
         }
       }
     }
@@ -164369,7 +164368,8 @@ ${newComment.split("\n").map((c) => ` * ${c}`).join("\n")}
       }
       return true;
     }
-    function getNodeDisplayPart(text, node, sourceFile) {
+    function getNodeDisplayPart(text, node) {
+      const sourceFile = node.getSourceFile();
       return {
         text,
         span: createTextSpanFromNode(node, sourceFile),
diff --git a/src/server/session.ts b/src/server/session.ts
index ed3872c8f4038..44c7b0ea34467 100644
--- a/src/server/session.ts
+++ b/src/server/session.ts
@@ -1850,14 +1850,24 @@ export class Session<TMessage = string> implements EventSender {
             return {
                 ...hint,
                 position: scriptInfo.positionToLineOffset(position),
-                displayParts: displayParts?.map(({ text, span, file }) => ({
-                    text,
-                    span: span && {
-                        start: scriptInfo.positionToLineOffset(span.start),
-                        end: scriptInfo.positionToLineOffset(span.start + span.length),
-                        file: file!
+                displayParts: displayParts?.map(({ text, span, file }) => {
+                    if (span) {
+                        Debug.assertIsDefined(file, "Target file should be defined together with its span.");
+                        const scriptInfo = this.projectService.getScriptInfo(file)!;
+
+                        return {
+                            text,
+                            span: {
+                                start: scriptInfo.positionToLineOffset(span.start),
+                                end: scriptInfo.positionToLineOffset(span.start + span.length),
+                                file,
+                            },
+                        };
                     }
-                })),
+                    else {
+                        return { text };
+                    }
+                }),
             };
         });
     }
diff --git a/src/services/inlayHints.ts b/src/services/inlayHints.ts
index 770bca101e739..c626113e87a60 100644
--- a/src/services/inlayHints.ts
+++ b/src/services/inlayHints.ts
@@ -62,7 +62,6 @@ import {
     Signature,
     skipParentheses,
     some,
-    SourceFile,
     Symbol,
     SymbolFlags,
     SyntaxKind,
@@ -158,11 +157,11 @@ export function provideInlayHints(context: InlayHintsContext): InlayHint[] {
         return isArrowFunction(node) || isFunctionExpression(node) || isFunctionDeclaration(node) || isMethodDeclaration(node) || isGetAccessorDeclaration(node);
     }
 
-    function addParameterHints(text: string, parameter: Identifier, position: number, isFirstVariadicArgument: boolean, sourceFile: SourceFile | undefined) {
+    function addParameterHints(text: string, parameter: Identifier, position: number, isFirstVariadicArgument: boolean) {
         let hintText = `${isFirstVariadicArgument ? "..." : ""}${text}`;
         let displayParts: InlayHintDisplayPart[] | undefined;
         if (shouldUseInteractiveInlayHints(preferences)) {
-            displayParts = [getNodeDisplayPart(hintText, parameter, sourceFile!), { text: ":" }];
+            displayParts = [getNodeDisplayPart(hintText, parameter), { text: ":" }];
             hintText = "";
         }
         else {
@@ -249,7 +248,6 @@ export function provideInlayHints(context: InlayHintsContext): InlayHint[] {
         }
 
         let signatureParamPos = 0;
-        const sourceFile = shouldUseInteractiveInlayHints(preferences) ? expr.getSourceFile() : undefined;
         for (const originalArg of args) {
             const arg = skipParentheses(originalArg);
             if (shouldShowLiteralParameterNameHintsOnly(preferences) && !isHintableLiteral(arg)) {
@@ -286,7 +284,7 @@ export function provideInlayHints(context: InlayHintsContext): InlayHint[] {
                     continue;
                 }
 
-                addParameterHints(name, parameter, originalArg.getStart(), isFirstVariadicArgument, sourceFile);
+                addParameterHints(name, parameter, originalArg.getStart(), isFirstVariadicArgument);
             }
         }
     }
@@ -436,7 +434,8 @@ export function provideInlayHints(context: InlayHintsContext): InlayHint[] {
         return true;
     }
 
-    function getNodeDisplayPart(text: string, node: Node, sourceFile: SourceFile): InlayHintDisplayPart {
+    function getNodeDisplayPart(text: string, node: Node): InlayHintDisplayPart {
+        const sourceFile = node.getSourceFile();
         return {
             text,
             span: createTextSpanFromNode(node, sourceFile),
diff --git a/tests/baselines/reference/inlayHintsInteractiveMultifileFunctionCalls.baseline b/tests/baselines/reference/inlayHintsInteractiveMultifileFunctionCalls.baseline
new file mode 100644
index 0000000000000..47ac8e6d4ad00
--- /dev/null
+++ b/tests/baselines/reference/inlayHintsInteractiveMultifileFunctionCalls.baseline
@@ -0,0 +1,21 @@
+helperB("hello, world!");
+        ^
+{
+  "text": "",
+  "position": 45,
+  "kind": "Parameter",
+  "whitespaceAfter": true,
+  "displayParts": [
+    {
+      "text": "bParam",
+      "span": {
+        "start": 61,
+        "length": 6
+      },
+      "file": "/tests/cases/fourslash/bbb.mts"
+    },
+    {
+      "text": ":"
+    }
+  ]
+}
\ No newline at end of file
diff --git a/tests/cases/fourslash/inlayHintsInteractiveMultifileFunctionCalls.ts b/tests/cases/fourslash/inlayHintsInteractiveMultifileFunctionCalls.ts
new file mode 100644
index 0000000000000..4d68c05bde68b
--- /dev/null
+++ b/tests/cases/fourslash/inlayHintsInteractiveMultifileFunctionCalls.ts
@@ -0,0 +1,24 @@
+/// <reference path="fourslash.ts" />
+
+// @Target: esnext
+// @module: nodenext
+
+// @Filename: aaa.mts
+////import { helperB } from "./bbb.mjs";
+////helperB("hello, world!");
+
+// @Filename: bbb.mts
+////import { helperC } from "./ccc.mjs";
+
+////export function helperB(bParam: string) {
+////    helperC(bParam);
+////}
+
+// @Filename: ccc.mts
+////export function helperC(cParam: string) {}
+
+goTo.file("./aaa.mts");
+verify.baselineInlayHints(undefined, {
+    includeInlayParameterNameHints: "all",
+    interactiveInlayHints: true
+});