diff --git a/Python/ast.c b/Python/ast.c
index 8dc86c2..ce3b492 100644
--- a/Python/ast.c
+++ b/Python/ast.c
@@ -1688,7 +1688,7 @@
                 return NULL;
         }
     }
-    return arguments(posargs, posonlyargs, vararg, kwonlyargs, kwdefaults, kwarg, posdefaults, c->c_arena);
+    return arguments(posonlyargs, posargs, vararg, kwonlyargs, kwdefaults, kwarg, posdefaults, c->c_arena);
 }
 
 static expr_ty