diff --git a/tests/mutex_unlock_and_sleep/tests/01-run.py b/tests/mutex_unlock_and_sleep/tests/01-run.py
index 28d12e30af..955095373a 100755
--- a/tests/mutex_unlock_and_sleep/tests/01-run.py
+++ b/tests/mutex_unlock_and_sleep/tests/01-run.py
@@ -11,7 +11,7 @@ import sys
 
 
 def testfunc(child):
-    for i in range(20):
+    for i in range(10):
         child.expect(r"\[ALIVE\] alternated \d+k times.")