diff --git a/scripts/deploy.sh b/scripts/deploy.sh
index b5ff1d6dc..d7717b23c 100755
--- a/scripts/deploy.sh
+++ b/scripts/deploy.sh
@@ -8,7 +8,7 @@ TARGET_REPO_URL="https://$GITHUB_AUTH_TOKEN@github.com/chartjs/chartjs.github.io
 VERSION_REGEX='[[:digit:]]+.[[:digit:]]+.[[:digit:]]+(-.*)?'
 
 # Make sure that this script is executed only for the release and master branches
-if [ "$TRAVIS_BRANCH" =~ ^release.*$ ]; then
+if [[ "$TRAVIS_BRANCH" =~ ^release.*$ ]]; then
     # Travis executes this script from the repository root, so at the same level than package.json
     VERSION=$(node -p -e "require('./package.json').version")
 elif [ "$TRAVIS_BRANCH" == "master" ]; then