--- a/toolkit/components/places/Database.cpp
+++ b/toolkit/components/places/Database.cpp
@@ -242,18 +242,17 @@ SetJournalMode(nsCOMPtr<mozIStorageConne
       return JOURNAL_TRUNCATE;
     }
     if (journalMode.EqualsLiteral("memory")) {
       return JOURNAL_MEMORY;
     }
     if (journalMode.EqualsLiteral("wal")) {
       return JOURNAL_WAL;
     }
-    // This is an unknown journal.
-    MOZ_ASSERT(true);
+    MOZ_ASSERT(false, "Got an unknown journal mode.");
   }
 
   return JOURNAL_DELETE;
 }
 
 nsresult
 CreateRoot(nsCOMPtr<mozIStorageConnection>& aDBConn,
            const nsCString& aRootName, const nsCString& aGuid,