diff --git a/src/UnlockManager.cpp b/src/UnlockManager.cpp
index b12331570b..6e0a856801 100644
--- a/src/UnlockManager.cpp
+++ b/src/UnlockManager.cpp
@@ -564,10 +564,18 @@ void UnlockManager::Load()
 
 	// Make sure that we don't have duplicate unlock IDs. This can cause problems
 	// with UnlockCelebrate and with codes.
-	FOREACH_CONST( UnlockEntry, m_UnlockEntries, ue )
-		FOREACH_CONST( UnlockEntry, m_UnlockEntries, ue2 )
-			if( ue != ue2 )
-				ASSERT_M( ue->m_sEntryID != ue2->m_sEntryID, ssprintf("duplicate unlock entry id %s",ue->m_sEntryID.c_str()) );
+	unsigned size = m_UnlockEntries.size();
+	for (unsigned i = 0; i < size - 1; ++i)
+	{
+		UnlockEntry const &ue1 = m_UnlockEntries[i];
+		for (unsigned j = i + 1; j < size; ++j)
+		{
+			UnlockEntry const &ue2 = m_UnlockEntries[j];
+			// at this point, these two are definitely different. Assert.
+			ASSERT_M( ue1.m_sEntryID != ue2.m_sEntryID, ssprintf("duplicate unlock entry id %s", ue1.m_sEntryID.c_str()));
+			
+		}
+	}
 
 	for (UnlockEntry &e : m_UnlockEntries)
 	{