diff --git a/run_tests.sh b/run_tests.sh
index 9ac346f..b8e4beb 100644
--- a/run_tests.sh
+++ b/run_tests.sh
@@ -1,10 +1,14 @@
 #!/bin/bash
 
+set -a
 set -e
 set -x
-#export PYTHONPATH=${PYTHONPATH:.}
+default_pythonpath=$PYTHONPATH:.
+export PYTHONPATH=${default_pythonpath:-.}
+>&2 echo using pythonpath $PYTHONPATH
 for f in `ls tests/*.py`; do
 	python $f
 done
 set +x
 set +e
+set +a