diff --git a/travis_script.sh b/travis_script.sh
index 8ab424de2..e616eee44 100755
--- a/travis_script.sh
+++ b/travis_script.sh
@@ -1,5 +1,7 @@
 #!/bin/bash
 set -ev
+unset -f cd
+shell_session_update() { :; }
 if [ "${TRAVIS_BRANCH}" = "ci" ]; then
   yarn run unit
   yarn run unit:coverage