diff --git a/tools/testing/selftests/perf_events/watermark_signal.c b/tools/testing/selftests/perf_events/watermark_signal.c
index 0f64b9b17081..a84709cabd8b 100644
--- a/tools/testing/selftests/perf_events/watermark_signal.c
+++ b/tools/testing/selftests/perf_events/watermark_signal.c
@@ -102,7 +102,7 @@ TEST(watermark_signal)
 	}
 
 	p = mmap(NULL, 2 * page_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
-	if (p == NULL) {
+	if (p == MAP_FAILED) {
 		perror("mmap");
 		goto cleanup;
 	}