diff --git a/python/python_test.go b/python/python_test.go
index c6b8451..3f719f8 100644
--- a/python/python_test.go
+++ b/python/python_test.go
@@ -370,7 +370,7 @@
 	if !baseOk {
 		t.Fatalf("%s is not Python module!", name)
 	}
-	sub, subOk := base.subModule.(*PythonBinary)
+	sub, subOk := base.subModule.(*pythonBinaryBase)
 	if !subOk {
 		t.Fatalf("%s is not Python binary!", name)
 	}