diff --git a/unittests/Basic/SourceManagerTest.cpp b/unittests/Basic/SourceManagerTest.cpp
index bb20faa..443d077 100644
--- a/unittests/Basic/SourceManagerTest.cpp
+++ b/unittests/Basic/SourceManagerTest.cpp
@@ -58,6 +58,9 @@
                                       bool IsInclusionDirective) {
     return ModuleLoadResult();
   }
+
+  virtual void makeModuleVisible(Module *Mod,
+                                 Module::NameVisibilityKind Visibility) { }
 };
 
 TEST_F(SourceManagerTest, isBeforeInTranslationUnit) {