diff --git a/include/llvm/ADT/ImmutableSet.h b/include/llvm/ADT/ImmutableSet.h
index 7c070d7a7f2..70fc1a69145 100644
--- a/include/llvm/ADT/ImmutableSet.h
+++ b/include/llvm/ADT/ImmutableSet.h
@@ -331,6 +331,7 @@ private:
 
     uint32_t X = ComputeDigest(getLeft(), getRight(), getValue());
     Digest = X;
+    MarkedCachedDigest();
     return X;
   }
 };