diff --git a/py/modbuiltins.c b/py/modbuiltins.c
index 5461816af0..5d4ec8ffe4 100644
--- a/py/modbuiltins.c
+++ b/py/modbuiltins.c
@@ -173,46 +173,24 @@ STATIC mp_obj_t mp_builtin_chr(mp_obj_t o_in) {
 MP_DEFINE_CONST_FUN_OBJ_1(mp_builtin_chr_obj, mp_builtin_chr);
 
 STATIC mp_obj_t mp_builtin_dir(size_t n_args, const mp_obj_t *args) {
-    // TODO make this function more general and less of a hack
-
-    mp_obj_dict_t *dict = NULL;
-    mp_map_t *members = NULL;
-    if (n_args == 0) {
-        // make a list of names in the local name space
-        dict = mp_locals_get();
-    } else { // n_args == 1
-        // make a list of names in the given object
-        if (MP_OBJ_IS_TYPE(args[0], &mp_type_module)) {
-            dict = mp_obj_module_get_globals(args[0]);
-        } else {
-            mp_obj_type_t *type;
-            if (MP_OBJ_IS_TYPE(args[0], &mp_type_type)) {
-                type = MP_OBJ_TO_PTR(args[0]);
-            } else {
-                type = mp_obj_get_type(args[0]);
-            }
-            if (type->locals_dict != NULL && type->locals_dict->base.type == &mp_type_dict) {
-                dict = type->locals_dict;
-            }
-        }
-        if (mp_obj_is_instance_type(mp_obj_get_type(args[0]))) {
-            mp_obj_instance_t *inst = MP_OBJ_TO_PTR(args[0]);
-            members = &inst->members;
-        }
-    }
-
     mp_obj_t dir = mp_obj_new_list(0, NULL);
-    if (dict != NULL) {
+    if (n_args == 0) {
+        // Make a list of names in the local namespace
+        mp_obj_dict_t *dict = mp_locals_get();
         for (size_t i = 0; i < dict->map.alloc; i++) {
             if (MP_MAP_SLOT_IS_FILLED(&dict->map, i)) {
                 mp_obj_list_append(dir, dict->map.table[i].key);
             }
         }
-    }
-    if (members != NULL) {
-        for (size_t i = 0; i < members->alloc; i++) {
-            if (MP_MAP_SLOT_IS_FILLED(members, i)) {
-                mp_obj_list_append(dir, members->table[i].key);
+    } else { // n_args == 1
+        // Make a list of names in the given object
+        // Implemented by probing all possible qstrs with mp_load_method_maybe
+        size_t nqstr = QSTR_TOTAL();
+        for (size_t i = 1; i < nqstr; ++i) {
+            mp_obj_t dest[2];
+            mp_load_method_maybe(args[0], i, dest);
+            if (dest[0] != MP_OBJ_NULL) {
+                mp_obj_list_append(dir, MP_OBJ_NEW_QSTR(i));
             }
         }
     }
diff --git a/tests/basics/builtin_dir.py b/tests/basics/builtin_dir.py
index 16e7e669e4..c15a76f4c6 100644
--- a/tests/basics/builtin_dir.py
+++ b/tests/basics/builtin_dir.py
@@ -17,3 +17,22 @@ foo = Foo()
 print('__init__' in dir(foo))
 print('x' in dir(foo))
 
+# dir of subclass
+class A:
+    def a():
+        pass
+class B(A):
+    def b():
+        pass
+d = dir(B())
+print(d.count('a'), d.count('b'))
+
+# dir of class with multiple bases and a common parent
+class C(A):
+    def c():
+        pass
+class D(B, C):
+    def d():
+        pass
+d = dir(D())
+print(d.count('a'), d.count('b'), d.count('c'), d.count('d'))