diff --git a/script/docs_auto_deploy.sh b/script/docs_auto_deploy.sh
index b27ba31..b0a8328 100644
--- a/script/docs_auto_deploy.sh
+++ b/script/docs_auto_deploy.sh
@@ -60,7 +60,7 @@ git config user.email "$COMMIT_AUTHOR_EMAIL"
 git diff --exit-code > /dev/null || exitcode=$?
 echo "git diff exit code: $exitcode"
 
-if [ -z $(git diff --exit-code  > /dev/null) ]; then
+if [ -z `git diff --exit-code  > /dev/null` ]; then
     echo "No changes to the documentation on this push; exiting."
     exit 0
 fi