diff --git a/src/testlib/3rdparty/valgrind_p.h b/src/testlib/3rdparty/valgrind_p.h
index 6380a9f28d..bbce1b24d6 100644
--- a/src/testlib/3rdparty/valgrind_p.h
+++ b/src/testlib/3rdparty/valgrind_p.h
@@ -259,6 +259,7 @@ typedef
                      : "cc", "memory"                             \
                     );                                            \
     _zzq_rlval = _zzq_result;                                     \
+    (void)_zzq_rlval;                                             \
   }
 
 #define VALGRIND_GET_NR_CONTEXT(_zzq_rlval)                       \