diff --git a/src/core/compact_object_test.cc b/src/core/compact_object_test.cc
index 601936dfb..5fbb4cddb 100644
--- a/src/core/compact_object_test.cc
+++ b/src/core/compact_object_test.cc
@@ -578,7 +578,7 @@ TEST_F(CompactObjectTest, DefragHash) {
 
 TEST_F(CompactObjectTest, DefragSet) {
   // This is still not implemented
-  StringSet* s = new StringSet();
+  StringSet* s = CompactObj::AllocateMR<StringSet>();
   s->Add("str");
   cobj_.InitRobj(OBJ_SET, kEncodingStrMap2, s);
   ASSERT_FALSE(cobj_.DefragIfNeeded(0.8));