diff --git a/tools/perf/bench/numa.c b/tools/perf/bench/numa.c
index 5049d6357a46..7500d959d7eb 100644
--- a/tools/perf/bench/numa.c
+++ b/tools/perf/bench/numa.c
@@ -293,7 +293,7 @@ static void bind_to_memnode(int node)
 	if (node == -1)
 		return;
 
-	BUG_ON(g->p.nr_nodes > (int)sizeof(nodemask));
+	BUG_ON(g->p.nr_nodes > (int)sizeof(nodemask)*8);
 	nodemask = 1L << node;
 
 	ret = set_mempolicy(MPOL_BIND, &nodemask, sizeof(nodemask)*8);