diff --git a/lang/object.c b/lang/object.c
index 027f1ad..71a1e78 100644
--- a/lang/object.c
+++ b/lang/object.c
@@ -29,17 +29,18 @@
 	abort_if(object == NULL, "object_priv: no object");
 	struct object *obj = (struct object *)object;
 	abort_if(obj->class_data != class, "object_priv: incompatible class");
-	return object->priv_data;
+	return obj->priv_data;
 }
 
-void object_hold(Object obj) {
-	abort_if(obj == NULL, "object_hold holding NULL");
+void object_hold(Object object) {
+	abort_if(object == NULL, "object_hold holding NULL");
+	struct object *obj = (struct object *)object;
 	atomic_fetch_add_explicit(&obj->ref_count, 1, memory_order_relaxed);
 }
 
 void object_drop(Object *objptr) {
 	abort_if(*objptr == NULL, "object_drop dropping NULL");
-	Object obj = *objptr;
+	struct object *obj = (struct object *)*objptr;
 	atomic_int count = atomic_fetch_sub_explicit(
 		&obj->ref_count, 1, memory_order_relaxed);
 	if (count == 1) {
@@ -50,7 +51,8 @@
 	*objptr = NULL;
 }
 
-void dispatch_call(VmState state, Object obj, const char *name) {
+void dispatch_call(VmState state, Object object, const char *name) {
+	struct object *obj = (struct object *)object;
 	struct object_call *call = obj->class_data->calls;
 	while (call->name != NULL) {
 		if (strcmp(call->name, name) == 0) {
diff --git a/lang/types.h b/lang/types.h
index 5c38c8d..1dfebae 100644
--- a/lang/types.h
+++ b/lang/types.h
@@ -4,9 +4,7 @@
 #ifndef TYPES_H
 #define TYPES_H
 
-struct object;
-
-typedef struct object *Object;
+typedef void *Object;
 typedef void *VmState;
 
 #endif