diff --git a/internal/gitaly/service/operations/commit_files.go b/internal/gitaly/service/operations/commit_files.go
index 24f376801ea10012c3fffa982fbd3acd7b80b935..6063a1137a33daf5163e6b1abb08a19938dfafd3 100644
--- a/internal/gitaly/service/operations/commit_files.go
+++ b/internal/gitaly/service/operations/commit_files.go
@@ -80,7 +80,7 @@ func (s *Server) UserCommitFiles(stream gitalypb.OperationService_UserCommitFile
 				},
 			)
 		case errors.As(err, &customHookErr):
-			return structerr.NewPermissionDenied("denied by custom hooks").WithDetail(
+			return structerr.NewPermissionDenied("Error: Denied by custom hooks.").WithDetail(
 				&gitalypb.UserCommitFilesError{
 					Error: &gitalypb.UserCommitFilesError_CustomHook{
 						CustomHook: customHookErr.Proto(),
diff --git a/internal/gitaly/service/operations/commit_files_test.go b/internal/gitaly/service/operations/commit_files_test.go
index b2293d3c8a3d6f73dae91ac6ac080584b9b7a15a..b68579a9f9d57b2537168ec9b78748439b4f6dc9 100644
--- a/internal/gitaly/service/operations/commit_files_test.go
+++ b/internal/gitaly/service/operations/commit_files_test.go
@@ -1054,7 +1054,7 @@ func TestUserCommitFilesQuarantine(t *testing.T) {
 	require.NoError(t, stream.Send(actionContentRequest("content")))
 	_, err = stream.CloseAndRecv()
 
-	testhelper.RequireGrpcError(t, structerr.NewPermissionDenied("denied by custom hooks").WithDetail(
+	testhelper.RequireGrpcError(t, structerr.NewPermissionDenied("Error: Denied by custom hooks.").WithDetail(
 		&gitalypb.UserCommitFilesError{
 			Error: &gitalypb.UserCommitFilesError_CustomHook{
 				CustomHook: &gitalypb.CustomHookError{
@@ -1498,7 +1498,7 @@ func TestFailedUserCommitFilesRequestDueToHooks(t *testing.T) {
 			expectedOut := fmt.Sprintf("GL_ID=%s GL_USERNAME=%s\n",
 				gittest.TestUser.GlId, gittest.TestUser.GlUsername)
 
-			testhelper.RequireGrpcError(t, structerr.NewPermissionDenied("denied by custom hooks").WithDetail(
+			testhelper.RequireGrpcError(t, structerr.NewPermissionDenied("Error: Denied by custom hooks.").WithDetail(
 				&gitalypb.UserCommitFilesError{
 					Error: &gitalypb.UserCommitFilesError_CustomHook{
 						CustomHook: &gitalypb.CustomHookError{