diff --git a/jenkins/RO/start_build b/jenkins/RO/start_build
index b633679..f3d2117 100755
--- a/jenkins/RO/start_build
+++ b/jenkins/RO/start_build
@@ -34,7 +34,7 @@
 	cd $OSM_MDG
 fi
 if [ $# -gt 0 ]; then
-	git checkout $1
+	git checkout $1 || FATAL "git checkout '$1' didn't work"
 fi
 
 INFO "starting build"