diff --git a/tests.sh b/tests.sh
index 77c7496..61f3589 100755
--- a/tests.sh
+++ b/tests.sh
@@ -6,6 +6,8 @@
 set -ev
 
 # PEP8 tests
+which pycodestyle 2>/dev/null
+[ "$?" != "0" ] && echo "Install pycodestyle" && exit 1
 pycodestyle --ignore=W605 dotdrop/
 pycodestyle tests/
 pycodestyle scripts/