diff --git a/libcxx/include/__iterator/distance.h b/libcxx/include/__iterator/distance.h
--- a/libcxx/include/__iterator/distance.h
+++ b/libcxx/include/__iterator/distance.h
@@ -74,12 +74,8 @@
 
   template<class _Ip, sized_sentinel_for<decay_t<_Ip>> _Sp>
   _LIBCPP_HIDE_FROM_ABI
-  constexpr iter_difference_t<_Ip> operator()(_Ip&& __first, _Sp __last) const {
-    if constexpr (sized_sentinel_for<_Sp, __uncvref_t<_Ip>>) {
-      return __last - __first;
-    } else {
-      return __last - decay_t<_Ip>(__first);
-    }
+  constexpr iter_difference_t<decay_t<_Ip>> operator()(_Ip&& __first, _Sp __last) const {
+    return __last - static_cast<const decay_t<_Ip>&>(__first);
   }
 
   template<range _Rp>