diff --git a/libnativeloader/native_loader_test.cpp b/libnativeloader/native_loader_test.cpp
index 614188b..aa9d5e1 100644
--- a/libnativeloader/native_loader_test.cpp
+++ b/libnativeloader/native_loader_test.cpp
@@ -98,7 +98,7 @@
           if (namespaces.find(name) != namespaces.end()) {
             return namespaces[name];
           }
-          return nullptr;
+          return TO_MOCK_NAMESPACE(TO_ANDROID_NAMESPACE("(namespace not found"));
         }));
   }