diff --git a/python/python.go b/python/python.go
index 945e264..e4c8e94 100644
--- a/python/python.go
+++ b/python/python.go
@@ -300,7 +300,7 @@
 }
 
 func (p *Module) hasSrcExt(ctx android.BottomUpMutatorContext, ext string) bool {
-	return hasSrcExt(p.properties.Srcs, protoExt)
+	return hasSrcExt(p.properties.Srcs, ext)
 }
 
 func (p *Module) DepsMutator(ctx android.BottomUpMutatorContext) {