diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index 1c4e467bbbe9..cf644b45b179 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,5 +1,10 @@
 2018-06-22  Jonathan Wakely  <jwakely@redhat.com>
 
+	PR libstdc++/86280
+	* include/experimental/memory_resource
+	(__resource_adaptor_common::_AlignMgr::_M_token_size): Use type large
+	enough for result of left shift.
+
 	PR libstdc++/86138
 	* include/bits/basic_string.tcc:
 	[__cplusplus > 201402 && !_GLIBCXX_USE_CXX11_ABI]
diff --git a/libstdc++-v3/include/experimental/memory_resource b/libstdc++-v3/include/experimental/memory_resource
index 8f5a8df14c95..1965fdcfe73b 100644
--- a/libstdc++-v3/include/experimental/memory_resource
+++ b/libstdc++-v3/include/experimental/memory_resource
@@ -326,7 +326,7 @@ namespace pmr {
 	  return 1;
 	if (_M_align <= (1ul << (sizeof(short) * __CHAR_BIT__)))
 	  return sizeof(short);
-	if (_M_align <= (1ul << (sizeof(int) * __CHAR_BIT__)))
+	if (_M_align <= (1ull << (sizeof(int) * __CHAR_BIT__)))
 	  return sizeof(int);
 	return sizeof(char*);
       }