diff --git a/clang/lib/Serialization/ASTReader.cpp b/clang/lib/Serialization/ASTReader.cpp
index 287bab8c3cc8a..836b05de94688 100644
--- a/clang/lib/Serialization/ASTReader.cpp
+++ b/clang/lib/Serialization/ASTReader.cpp
@@ -6630,6 +6630,9 @@ bool ASTReader::ParseHeaderSearchPaths(const RecordData &Record, bool Complain,
     HSOpts.VFSOverlayFiles.emplace_back(std::move(VFSOverlayFile));
   }
 
+  std::string Blah = ReadString(Record, Idx);
+  (void)Blah;
+
   return Listener.ReadHeaderSearchPaths(HSOpts, Complain);
 }
 
diff --git a/clang/lib/Serialization/ASTWriter.cpp b/clang/lib/Serialization/ASTWriter.cpp
index ca1053a44e4d5..aa9f882c5744b 100644
--- a/clang/lib/Serialization/ASTWriter.cpp
+++ b/clang/lib/Serialization/ASTWriter.cpp
@@ -1421,6 +1421,8 @@ void ASTWriter::writeUnhashedControlBlock(Preprocessor &PP) {
     for (StringRef VFSOverlayFile : HSOpts.VFSOverlayFiles)
       AddString(VFSOverlayFile, Record);
 
+    AddString("Blah", Record);
+
     Stream.EmitRecord(HEADER_SEARCH_PATHS, Record);
   }