diff --git a/cmd/cue/cmd/common_test.go b/cmd/cue/cmd/common_test.go
index 018531c..d2c7184 100644
--- a/cmd/cue/cmd/common_test.go
+++ b/cmd/cue/cmd/common_test.go
@@ -24,7 +24,7 @@
 
 var _ = errors.Print
 
-var update = flag.Bool("update", false, "update the test files")
+var update = flag.Bool("update", os.Getenv("CUE_UPDATE") != "", "update the test files")
 
 func printConfig(t *testing.T) *errors.Config {
 	t.Helper()