diff --git a/vm/src/builtins/descriptor.rs b/vm/src/builtins/descriptor.rs
index 16340c3a62..408b0efc84 100644
--- a/vm/src/builtins/descriptor.rs
+++ b/vm/src/builtins/descriptor.rs
@@ -320,10 +320,13 @@ fn set_slot_at_object(
                 PySetterValue::Delete => obj.set_slot(offset, None),
             };
         }
-        MemberKind::ObjectEx => match value {
-            PySetterValue::Assign(v) => obj.set_slot(offset, Some(v)),
-            PySetterValue::Delete => obj.set_slot(offset, None),
-        },
+        MemberKind::ObjectEx => {
+            let value = match value {
+                PySetterValue::Assign(v) => Some(v),
+                PySetterValue::Delete => None,
+            };
+            obj.set_slot(offset, value);
+        }
     }
 
     Ok(())
diff --git a/vm/src/builtins/type.rs b/vm/src/builtins/type.rs
index 296afff17c..15df5ff3c5 100644
--- a/vm/src/builtins/type.rs
+++ b/vm/src/builtins/type.rs
@@ -934,9 +934,14 @@ impl Constructor for PyType {
                 None
             };
 
-        let base_member_count = base.slots.member_count;
-        let member_count: usize =
-            base.slots.member_count + heaptype_slots.as_ref().map(|x| x.len()).unwrap_or(0);
+        // FIXME: this is a temporary fix. multi bases with multiple slots will break object
+        let base_member_count = bases
+            .iter()
+            .map(|base| base.slots.member_count)
+            .max()
+            .unwrap();
+        let heaptype_member_count = heaptype_slots.as_ref().map(|x| x.len()).unwrap_or(0);
+        let member_count: usize = base_member_count + heaptype_member_count;
 
         let flags = PyTypeFlags::heap_type_flags() | PyTypeFlags::HAS_DICT;
         let (slots, heaptype_ext) = {