diff --git a/scripts/dss-services.sh b/scripts/dss-services.sh
index b7748a9..544b9e6 100755
--- a/scripts/dss-services.sh
+++ b/scripts/dss-services.sh
@@ -104,7 +104,7 @@ start_service() {
       return 0
     fi
     sleep 1
-    ((waited++))
+    ((waited+=1))
   done
 
   log_error "$service failed to start (check $log)"