diff --git a/master.cfg b/master.cfg
index 88ee9cc..170ef01 100644
--- a/master.cfg
+++ b/master.cfg
@@ -249,7 +249,7 @@ do more than 3 updates at a time."""
     name = "random wait for clone"
     description = r"randomly waiting before git fetching"
     descriptionDone = r"waited before git fetching"
-    command = ['sleep', WithProperties (r"%ss", r'randomWait')]
+    command = ['sleep', WithProperties (r"%s", r'randomWait')]
 
 class CloneOrUpdateGDBMasterRepo (Git):
     """This build step updates the so-called "master" git repository.  For