diff --git a/run-cov.sh b/run-cov.sh
index d18e58f..c7533a2 100755
--- a/run-cov.sh
+++ b/run-cov.sh
@@ -1,3 +1,5 @@
+#!/bin/sh
+
 export PYTHONPATH=.;
 pip install -e .
 py.test jellyfish/test.py --cov jellyfish --cov-report html