diff --git a/RERUN b/RERUN
index af614d1e..83dcdec8 100755
--- a/RERUN
+++ b/RERUN
@@ -2,6 +2,11 @@
 # rerun last toplev line from tl-tester log, optionally with a prefix (like python -mpdb)
 # tl-tester >& log
 # RERUN log python -mpdb
+if [ "$1" == "--notltester" ] ; then
+	shift
+else
+	export TL_TESTER=1
+fi
 L="$1"
 shift
 T=$(grep Line.*toplev "$L"  | tail -1 | sed 's/Line [0-9]* //')