diff --git a/tools/SourceKit/lib/SwiftLang/SwiftASTManager.cpp b/tools/SourceKit/lib/SwiftLang/SwiftASTManager.cpp
index ea8d54b09fb41..886bc6d01901e 100644
--- a/tools/SourceKit/lib/SwiftLang/SwiftASTManager.cpp
+++ b/tools/SourceKit/lib/SwiftLang/SwiftASTManager.cpp
@@ -168,6 +168,7 @@ void InvocationOptions::profile(llvm::FoldingSetNodeID &ID) const {
   for (auto &Arg : Args)
     ID.AddString(Arg);
   ID.AddString(PrimaryFile);
+  ID.AddPointer(FileSystem.get());
 }
 
 //===----------------------------------------------------------------------===//