--- a/testing/vcttesting/environment.py
+++ b/testing/vcttesting/environment.py
@@ -116,17 +116,17 @@ def install_mercurials(venv, hg="hg"):
     """Install supported Mercurial versions in a central location."""
     VERSIONS = [
         "6.1.4",
         "6.2.3",
         "6.3.2",
         "6.4.3",
         "6.5.2",
         "6.6.3",
-        "6.7.3",
+        "6.7.4",
     ]
 
     hg_dir = os.path.join("/app", "venv", "hg")
     mercurials = os.path.join(venv["path"], "mercurials")
 
     # Setting HGRCPATH to an empty value stops the global and user hgrc from
     # being loaded. These could interfere with behavior we expect from
     # vanilla Mercurial.