diff --git a/clang/lib/Frontend/CompilerInstance.cpp b/clang/lib/Frontend/CompilerInstance.cpp
index 1c5b322..3492bf1 100644
--- a/clang/lib/Frontend/CompilerInstance.cpp
+++ b/clang/lib/Frontend/CompilerInstance.cpp
@@ -329,7 +329,8 @@
 
   PP->setPreprocessedOutput(getPreprocessorOutputOpts().ShowCPP);
 
-  PP->getHeaderSearchInfo().setModuleCachePath(getSpecificModuleCachePath());
+  if (PP->getLangOpts().Modules)
+    PP->getHeaderSearchInfo().setModuleCachePath(getSpecificModuleCachePath());
 
   // Handle generating dependencies, if requested.
   const DependencyOutputOptions &DepOpts = getDependencyOutputOpts();