diff --git a/legacy/eobj/src/lib/eo.c b/legacy/eobj/src/lib/eo.c
index 4c5b9c6035..c8f9d3b8f6 100644
--- a/legacy/eobj/src/lib/eo.c
+++ b/legacy/eobj/src/lib/eo.c
@@ -592,6 +592,22 @@ _eo_class_base_op_init(Eo_Class *klass)
    *(desc->ops.base_op_id) = EO_CLASS_ID_TO_BASE_ID(klass->class_id);
 }
 
+#ifndef NDEBUG
+static Eina_Bool
+_eo_class_mro_has(const Eo_Class *klass, const Eo_Class *find)
+{
+   const Eo_Class **itr;
+   for (itr = klass->mro ; *itr ; itr++)
+     {
+        if (*itr == find)
+          {
+             return EINA_TRUE;
+          }
+     }
+   return EINA_FALSE;
+}
+#endif
+
 static Eina_List *
 _eo_class_mro_add(Eina_List *mro, const Eo_Class *klass)
 {
@@ -889,9 +905,6 @@ eo_class_new(const Eo_Class_Description *desc, Eo_Class_Id id, const Eo_Class *p
                {
                 case EO_CLASS_TYPE_REGULAR:
                 case EO_CLASS_TYPE_REGULAR_NO_INSTANT:
-                   /* Ignore regular classes ATM. */
-                   break;
-
                 case EO_CLASS_TYPE_INTERFACE:
                 case EO_CLASS_TYPE_MIXIN:
                    extn_list = eina_list_append(extn_list, extn);
@@ -1453,7 +1466,7 @@ eo_data_get(const Eo *obj, const Eo_Class *klass)
    EO_MAGIC_RETURN_VAL(klass, EO_CLASS_EINA_MAGIC, NULL);
 
 #ifndef NDEBUG
-   if ((klass->desc->type == EO_CLASS_TYPE_INTERFACE) || !eo_isa(obj, klass))
+   if (!_eo_class_mro_has(obj->klass, klass))
      {
         ERR("Tried getting data of class '%s' from object of class '%s', but the former is not a direct inheritance of the latter.", klass->desc->name, obj->klass->desc->name);
         return NULL;
diff --git a/legacy/eobj/src/tests/eo_suite/eo_test_general.c b/legacy/eobj/src/tests/eo_suite/eo_test_general.c
index 9676263848..ef62cac06c 100644
--- a/legacy/eobj/src/tests/eo_suite/eo_test_general.c
+++ b/legacy/eobj/src/tests/eo_suite/eo_test_general.c
@@ -63,6 +63,83 @@ START_TEST(eo_data_fetch)
 }
 END_TEST
 
+START_TEST(eo_isa_tests)
+{
+   eo_init();
+
+   const Eo_Class *klass, *iface, *mixin;
+
+     {
+        /* Usually should be const, not const only for the test... */
+        static Eo_Class_Description class_desc = {
+             "Iface",
+             EO_CLASS_TYPE_INTERFACE,
+             EO_CLASS_DESCRIPTION_OPS(NULL, NULL, 0),
+             NULL,
+             0,
+             NULL,
+             NULL
+        };
+
+        iface = eo_class_new(&class_desc, 0, NULL, NULL);
+        fail_if(!iface);
+     }
+
+     {
+        /* Usually should be const, not const only for the test... */
+        static Eo_Class_Description class_desc = {
+             "Mixin",
+             EO_CLASS_TYPE_MIXIN,
+             EO_CLASS_DESCRIPTION_OPS(NULL, NULL, 0),
+             NULL,
+             0,
+             NULL,
+             NULL
+        };
+
+        mixin = eo_class_new(&class_desc, 0, NULL, NULL);
+        fail_if(!mixin);
+     }
+
+     {
+        /* Usually should be const, not const only for the test... */
+        static Eo_Class_Description class_desc = {
+             "Simple2",
+             EO_CLASS_TYPE_REGULAR,
+             EO_CLASS_DESCRIPTION_OPS(NULL, NULL, 0),
+             NULL,
+             10,
+             NULL,
+             NULL
+        };
+
+        klass = eo_class_new(&class_desc, 0, EO_BASE_CLASS, iface, mixin, NULL);
+        fail_if(!klass);
+     }
+
+   Eo *obj = eo_add(klass, NULL);
+   fail_if(!obj);
+   fail_if(eo_isa(obj, SIMPLE_CLASS));
+   fail_if(!eo_isa(obj, iface));
+   fail_if(!eo_isa(obj, mixin));
+   fail_if(!eo_isa(obj, klass));
+   fail_if(!eo_isa(obj, EO_BASE_CLASS));
+   eo_unref(obj);
+
+   obj = eo_add(SIMPLE_CLASS, NULL);
+   fail_if(!obj);
+   fail_if(eo_isa(obj, klass));
+   fail_if(eo_isa(obj, iface));
+   fail_if(eo_isa(obj, mixin));
+   fail_if(!eo_isa(obj, SIMPLE_CLASS));
+   fail_if(!eo_isa(obj, EO_BASE_CLASS));
+   eo_unref(obj);
+
+   eo_shutdown();
+}
+END_TEST
+
+
 START_TEST(eo_composite_tests)
 {
    eo_init();
@@ -531,6 +608,9 @@ START_TEST(eo_magic_checks)
         eo_unref((Eo *) buf);
         eo_del((Eo *) buf);
 
+        eo_isa((Eo *) buf, SIMPLE_CLASS);
+        eo_isa(obj, (Eo_Class *) buf);
+
         fail_if(0 != eo_ref_get((Eo *) buf));
 
         Eo *wref = NULL;
@@ -579,4 +659,5 @@ void eo_test_general(TCase *tc)
    tcase_add_test(tc, eo_man_free);
    tcase_add_test(tc, eo_static_classes);
    tcase_add_test(tc, eo_composite_tests);
+   tcase_add_test(tc, eo_isa_tests);
 }