diff --git a/pkgs/development/python-modules/google-cloud-testutils/default.nix b/pkgs/development/python-modules/google-cloud-testutils/default.nix
index e1f04575aaf1..7f22b14d12d3 100644
--- a/pkgs/development/python-modules/google-cloud-testutils/default.nix
+++ b/pkgs/development/python-modules/google-cloud-testutils/default.nix
@@ -11,14 +11,14 @@
 
 buildPythonPackage rec {
   pname = "google-cloud-testutils";
-  version = "1.6.0";
+  version = "1.6.4";
   pyproject = true;
 
   src = fetchFromGitHub {
     owner = "googleapis";
     repo = "python-test-utils";
     tag = "v${version}";
-    hash = "sha256-WxEFtYiWSl9ZmaduucdVpiCb2SUEVwUdY8jG8GHni7M=";
+    hash = "sha256-VTu/ElWZrSUrUBrfLPTBV4PMSQCRAyF9Ka7jKEqVzLk=";
   };
 
   build-system = [ setuptools ];
@@ -39,7 +39,7 @@ buildPythonPackage rec {
     description = "System test utilities for google-cloud-python";
     mainProgram = "lower-bound-checker";
     homepage = "https://github.com/googleapis/python-test-utils";
-    changelog = "https://github.com/googleapis/python-test-utils/blob/v${version}/CHANGELOG.md";
+    changelog = "https://github.com/googleapis/python-test-utils/blob/${src.tag}/CHANGELOG.md";
     license = lib.licenses.asl20;
     maintainers = [ lib.maintainers.sarahec ];
   };