diff --git a/clang/include/clang/APINotes/Types.h b/clang/include/clang/APINotes/Types.h
--- a/clang/include/clang/APINotes/Types.h
+++ b/clang/include/clang/APINotes/Types.h
@@ -532,7 +532,7 @@
 
     // Mask the bits.
     NullabilityPayload &=
-        ~(NullabilityKindMask << (index * NullabilityKindSize));
+        ~(static_cast<uint64_t>NullabilityKindMask << (index * NullabilityKindSize));
 
     // Set the value.
     unsigned kindValue = (static_cast<unsigned>(kind))