diff --git a/llvm/include/llvm/Support/TypeSize.h b/llvm/include/llvm/Support/TypeSize.h
index 0777005643a712..3efcdc486d36f2 100644
--- a/llvm/include/llvm/Support/TypeSize.h
+++ b/llvm/include/llvm/Support/TypeSize.h
@@ -211,7 +211,7 @@ class UnivariateLinearPolyBase {
   }
 
   template <typename U = ScalarTy>
-  friend std::enable_if_t<std::is_signed<U>::value, LeafTy>
+  friend typename std::enable_if_t<std::is_signed<U>::value, LeafTy>
   operator-(const LeafTy &LHS) {
     LeafTy Copy = LHS;
     return Copy *= -1;