diff --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp
index 02e153ff10737..33ad94e6795c8 100644
--- a/clang/lib/AST/ExprConstant.cpp
+++ b/clang/lib/AST/ExprConstant.cpp
@@ -240,15 +240,19 @@ namespace {
     /// True if the subobject was named in a manner not supported by C++11. Such
     /// lvalues can still be folded, but they are not core constant expressions
     /// and we cannot perform lvalue-to-rvalue conversions on them.
+    LLVM_PREFERRED_TYPE(bool)
     unsigned Invalid : 1;
 
     /// Is this a pointer one past the end of an object?
+    LLVM_PREFERRED_TYPE(bool)
     unsigned IsOnePastTheEnd : 1;
 
     /// Indicator of whether the first entry is an unsized array.
+    LLVM_PREFERRED_TYPE(bool)
     unsigned FirstEntryIsAnUnsizedArray : 1;
 
     /// Indicator of whether the most-derived object is an array element.
+    LLVM_PREFERRED_TYPE(bool)
     unsigned MostDerivedIsArrayElement : 1;
 
     /// The length of the path to the most-derived object of which this is a