diff --git a/fail2ban/server/utils.py b/fail2ban/server/utils.py
index 294d147f..8483b013 100644
--- a/fail2ban/server/utils.py
+++ b/fail2ban/server/utils.py
@@ -332,11 +332,9 @@ class Utils():
 					timeout_expr = lambda: time.time() > time0
 				else:
 					timeout_expr = timeout
-				if not interval:
-					interval = Utils.DEFAULT_SLEEP_INTERVAL
 			if timeout_expr():
 				break
-			stm = min(stm + interval, Utils.DEFAULT_SLEEP_TIME)
+			stm = min(stm + (interval or Utils.DEFAULT_SLEEP_INTERVAL), Utils.DEFAULT_SLEEP_TIME)
 			time.sleep(stm)
 		return ret