diff --git a/tests/rcutorture.c b/tests/rcutorture.c
index 49311c82ea..e8b2169e7d 100644
--- a/tests/rcutorture.c
+++ b/tests/rcutorture.c
@@ -413,7 +413,8 @@ static void gtest_stress_10_5(void)
 
 static void usage(int argc, char *argv[])
 {
-    fprintf(stderr, "Usage: %s [nreaders [ perf | stress ] ]\n", argv[0]);
+    fprintf(stderr, "Usage: %s [nreaders [ [r|u]perf | stress [duration]]\n",
+            argv[0]);
     exit(-1);
 }