diff --git a/src/testlib/3rdparty/valgrind_p.h b/src/testlib/3rdparty/valgrind_p.h
index 577c8f05e5b..8c6c132d6c8 100644
--- a/src/testlib/3rdparty/valgrind_p.h
+++ b/src/testlib/3rdparty/valgrind_p.h
@@ -872,7 +872,8 @@ typedef
                     /* results = r3 */                           \
                     "lgr %0, 3\n\t"                              \
                     : "=d" (_zzq_result)                         \
-                    : "a" (&_zzq_args[0]), "0" (_zzq_default)    \
+                    : "a" (&_zzq_args[0]),                       \
+                      "0" ((unsigned long int)_zzq_default)      \
                     : "cc", "2", "3", "memory"                   \
                    );                                            \
    _zzq_result;                                                  \