diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index e87c303d47b..a25a2e74574 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,10 @@
+2015-07-02  Uros Bizjak  <ubizjak@gmail.com>
+
+	* libsupc++/guard.cc (__test_and_acquire): Use __p after __atomic_load
+	to avoid unused variable warning.
+	(__set_and_release): Use __p after __atomic_store to avoid unused
+	variable warning.
+
 2015-07-01  Jonathan Wakely  <jwakely@redhat.com>
 
 	* include/bits/alloc_traits.h (__alloctr_rebind): Remove.
diff --git a/libstdc++-v3/libsupc++/guard.cc b/libstdc++-v3/libsupc++/guard.cc
index 4a2cfe938a9..d4a43734652 100644
--- a/libstdc++-v3/libsupc++/guard.cc
+++ b/libstdc++-v3/libsupc++/guard.cc
@@ -117,6 +117,7 @@ __test_and_acquire (__cxxabiv1::__guard *g)
   unsigned char __c;
   unsigned char *__p = reinterpret_cast<unsigned char *>(g);
   __atomic_load (__p, &__c,  __ATOMIC_ACQUIRE);
+  (void) __p;
   return _GLIBCXX_GUARD_TEST(&__c);
 }
 #  define _GLIBCXX_GUARD_TEST_AND_ACQUIRE(G) __test_and_acquire (G)
@@ -132,6 +133,7 @@ __set_and_release (__cxxabiv1::__guard *g)
   unsigned char *__p = reinterpret_cast<unsigned char *>(g);
   unsigned char val = 1;
   __atomic_store (__p, &val, __ATOMIC_RELEASE);
+  (void) __p;
 }
 #  define _GLIBCXX_GUARD_SET_AND_RELEASE(G) __set_and_release (G)
 # endif