diff --git a/llvm/include/llvm/ADT/STLExtras.h b/llvm/include/llvm/ADT/STLExtras.h
--- a/llvm/include/llvm/ADT/STLExtras.h
+++ b/llvm/include/llvm/ADT/STLExtras.h
@@ -1273,7 +1273,7 @@
 /// compares less than the first component of another std::pair.
 struct less_first {
   template <typename T> bool operator()(const T &lhs, const T &rhs) const {
-    return lhs.first < rhs.first;
+    return std::less<>()(lhs.first, rhs.first);
   }
 };
 
@@ -1281,7 +1281,7 @@
 /// compares less than the second component of another std::pair.
 struct less_second {
   template <typename T> bool operator()(const T &lhs, const T &rhs) const {
-    return lhs.second < rhs.second;
+    return std::less<>()(lhs.second, rhs.second);
   }
 };