diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index 1a0a485bd2c..050b027fbe5 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,9 @@
+2018-07-26  Jonathan Wakely  <jwakely@redhat.com>
+
+	PR libstdc++/86676
+	* testsuite/20_util/monotonic_buffer_resource/release.cc: Request
+	same alignment for post-release allocation.
+
 2018-07-25  Jonathan Wakely  <jwakely@redhat.com>
 
 	PR libstdc++/86676
diff --git a/libstdc++-v3/testsuite/20_util/monotonic_buffer_resource/release.cc b/libstdc++-v3/testsuite/20_util/monotonic_buffer_resource/release.cc
index ac70385961d..8aab4692d52 100644
--- a/libstdc++-v3/testsuite/20_util/monotonic_buffer_resource/release.cc
+++ b/libstdc++-v3/testsuite/20_util/monotonic_buffer_resource/release.cc
@@ -127,7 +127,7 @@ test04()
   VERIFY( mbr.upstream_resource() == &r );
   VERIFY( r.number_of_active_allocations() == 0 );
   // initial buffer should be used again now:
-  p = mbr.allocate(1000);
+  p = mbr.allocate(1000, 16);
   VERIFY( p == p_in_buffer );
   VERIFY( r.allocate_calls == 1 );
 }