diff --git a/src/cmd/go/go_test.go b/src/cmd/go/go_test.go
index 3cd3454..3ce3238 100644
--- a/src/cmd/go/go_test.go
+++ b/src/cmd/go/go_test.go
@@ -216,6 +216,7 @@
 	}
 	// Don't let these environment variables confuse the test.
 	os.Setenv("GOENV", "off")
+	os.Unsetenv("GOFLAGS")
 	os.Unsetenv("GOBIN")
 	os.Unsetenv("GOPATH")
 	os.Unsetenv("GIT_ALLOW_PROTOCOL")