diff --git a/clang/lib/Serialization/ASTWriter.cpp b/clang/lib/Serialization/ASTWriter.cpp
index 63d91708aeb02..6fa2cd681b191 100644
--- a/clang/lib/Serialization/ASTWriter.cpp
+++ b/clang/lib/Serialization/ASTWriter.cpp
@@ -1280,8 +1280,9 @@ void ASTWriter::WriteControlBlock(Preprocessor &PP, ASTContext &Context,
     SmallString<128> BaseDir;
     if (PP.getHeaderSearchInfo().getHeaderSearchOpts().ModuleFileHomeIsCwd) {
       // Use the current working directory as the base path for all inputs.
-      auto *CWD =
-          Context.getSourceManager().getFileManager().getDirectory(".").get();
+      auto CWD =
+          Context.getSourceManager().getFileManager().getOptionalDirectoryRef(
+              ".");
       BaseDir.assign(CWD->getName());
     } else {
       BaseDir.assign(WritingModule->Directory->getName());