diff --git a/Parser/asdl_c.py b/Parser/asdl_c.py
index fac9a7740a1..ab5fd229cc4 100755
--- a/Parser/asdl_c.py
+++ b/Parser/asdl_c.py
@@ -843,8 +843,9 @@ typedef struct {
 } AST_object;
 
 static void
-ast_dealloc(AST_object *self)
+ast_dealloc(PyObject *op)
 {
+    AST_object *self = (AST_object*)op;
     /* bpo-31095: UnTrack is needed before calling any callbacks */
     PyTypeObject *tp = Py_TYPE(self);
     PyObject_GC_UnTrack(self);
@@ -856,16 +857,18 @@ ast_dealloc(AST_object *self)
 }
 
 static int
-ast_traverse(AST_object *self, visitproc visit, void *arg)
+ast_traverse(PyObject *op, visitproc visit, void *arg)
 {
+    AST_object *self = (AST_object*)op;
     Py_VISIT(Py_TYPE(self));
     Py_VISIT(self->dict);
     return 0;
 }
 
 static int
-ast_clear(AST_object *self)
+ast_clear(PyObject *op)
 {
+    AST_object *self = (AST_object*)op;
     Py_CLEAR(self->dict);
     return 0;
 }
@@ -1651,9 +1654,9 @@ error:
 }
 
 static PyObject *
-ast_repr(AST_object *self)
+ast_repr(PyObject *self)
 {
-    return ast_repr_max_depth(self, 3);
+    return ast_repr_max_depth((AST_object*)self, 3);
 }
 
 static PyType_Slot AST_type_slots[] = {
@@ -1847,8 +1850,9 @@ static int add_ast_fields(struct ast_state *state)
 
         self.file.write(textwrap.dedent('''
             static int
-            init_types(struct ast_state *state)
+            init_types(void *arg)
             {
+                struct ast_state *state = arg;
                 if (init_identifiers(state) < 0) {
                     return -1;
                 }
@@ -2296,7 +2300,7 @@ def generate_module_def(mod, metadata, f, internal_h):
         };
 
         // Forward declaration
-        static int init_types(struct ast_state *state);
+        static int init_types(void *arg);
 
         static struct ast_state*
         get_ast_state(void)
diff --git a/Python/Python-ast.c b/Python/Python-ast.c
index 860447ef9ed..4a58c0973d1 100644
--- a/Python/Python-ast.c
+++ b/Python/Python-ast.c
@@ -19,7 +19,7 @@ struct validator {
 };
 
 // Forward declaration
-static int init_types(struct ast_state *state);
+static int init_types(void *arg);
 
 static struct ast_state*
 get_ast_state(void)
@@ -5044,8 +5044,9 @@ typedef struct {
 } AST_object;
 
 static void
-ast_dealloc(AST_object *self)
+ast_dealloc(PyObject *op)
 {
+    AST_object *self = (AST_object*)op;
     /* bpo-31095: UnTrack is needed before calling any callbacks */
     PyTypeObject *tp = Py_TYPE(self);
     PyObject_GC_UnTrack(self);
@@ -5057,16 +5058,18 @@ ast_dealloc(AST_object *self)
 }
 
 static int
-ast_traverse(AST_object *self, visitproc visit, void *arg)
+ast_traverse(PyObject *op, visitproc visit, void *arg)
 {
+    AST_object *self = (AST_object*)op;
     Py_VISIT(Py_TYPE(self));
     Py_VISIT(self->dict);
     return 0;
 }
 
 static int
-ast_clear(AST_object *self)
+ast_clear(PyObject *op)
 {
+    AST_object *self = (AST_object*)op;
     Py_CLEAR(self->dict);
     return 0;
 }
@@ -5852,9 +5855,9 @@ error:
 }
 
 static PyObject *
-ast_repr(AST_object *self)
+ast_repr(PyObject *self)
 {
-    return ast_repr_max_depth(self, 3);
+    return ast_repr_max_depth((AST_object*)self, 3);
 }
 
 static PyType_Slot AST_type_slots[] = {
@@ -6047,8 +6050,9 @@ static int add_ast_fields(struct ast_state *state)
 
 
 static int
-init_types(struct ast_state *state)
+init_types(void *arg)
 {
+    struct ast_state *state = arg;
     if (init_identifiers(state) < 0) {
         return -1;
     }