diff --git a/include/preview/__type_traits/is_add_assignable.h b/include/preview/__type_traits/is_add_assignable.h
index 0b0904e7..6d9a8ce2 100644
--- a/include/preview/__type_traits/is_add_assignable.h
+++ b/include/preview/__type_traits/is_add_assignable.h
@@ -13,6 +13,11 @@
 #include "preview/__type_traits/void_t.h"
 #include "preview/__utility/type_sequence.h"
 
+#ifdef _MSC_VER
+#pragma warning( push )
+#pragma warning( disable : 4244)
+#endif
+
 namespace preview {
 
 template<typename T, typename U, template<typename...> class Constraint = always_true,
@@ -26,4 +31,8 @@ struct is_add_assignable<T, U, Constraint, CallArgs, Proj, void_t<decltype(std::
 
 } // namespace preview
 
+#ifdef _MSC_VER
+#pragma warning( pop )
+#endif
+
 #endif // PREVIEW_TYPE_TRAITS_IS_ADD_ASSIGNABLE_H_
diff --git a/include/preview/__type_traits/is_subtract_assignable.h b/include/preview/__type_traits/is_subtract_assignable.h
index 0cbaa91f..cecef83d 100644
--- a/include/preview/__type_traits/is_subtract_assignable.h
+++ b/include/preview/__type_traits/is_subtract_assignable.h
@@ -13,6 +13,11 @@
 #include "preview/__type_traits/void_t.h"
 #include "preview/__utility/type_sequence.h"
 
+#ifdef _MSC_VER
+#pragma warning( push )
+#pragma warning( disable : 4244)
+#endif
+
 namespace preview {
 
 template<typename T, typename U, template<typename...> class Constraint = always_true,
@@ -26,4 +31,8 @@ struct is_subtract_assignable<T, U, Constraint, CallArgs, Proj, void_t<decltype(
 
 } // namespace preview
 
+#ifdef _MSC_VER
+#pragma warning( pop )
+#endif
+
 #endif // PREVIEW_TYPE_TRAITS_IS_SUBTRACT_ASSIGNABLE_H_