diff --git a/Parser/asdl_c.py b/Parser/asdl_c.py
index 5bb42ec..fdbbeaf 100755
--- a/Parser/asdl_c.py
+++ b/Parser/asdl_c.py
@@ -732,7 +732,7 @@
     f.close()
 
     if SRC_DIR:
-        p = "%s/%s-ast.c" % (SRC_DIR, mod.name)
+        p = os.path.join(SRC_DIR, str(mod.name) + "-ast.c")
     else:
         p = "%s-ast.c" % mod.name
     f = open(p, "wb")