diff --git a/contrib/scripts/live_ast b/contrib/scripts/live_ast
index 1beaef9f9e63f05b28682dbf7316bf5394768db0..331f7992b139638de9ef3a615c7d9dceb936bd55 100755
--- a/contrib/scripts/live_ast
+++ b/contrib/scripts/live_ast
@@ -168,7 +168,9 @@ gen_live_conf() {
 }
 
 command="$1"
-shift
+if [ $# -gt 0 ]; then
+  shift
+fi
 
 case "$command" in
 configure)