diff --git a/scripts/release.sh b/scripts/release.sh
index e697e2200..b64f03474 100755
--- a/scripts/release.sh
+++ b/scripts/release.sh
@@ -7,14 +7,14 @@ TMP_FOLDER=$2
 RELEASE_FOLDER=$3
 ENV=$4
 
-rm -rf $TMP_FOLDER/$RELEASE_FOLDER
-mkdir $TMP_FOLDER/$RELEASE_FOLDER
-git clone git@github.com:wallabag/wallabag.git $TMP_FOLDER/$RELEASE_FOLDER/$VERSION
-cd $TMP_FOLDER/$RELEASE_FOLDER/$VERSION && SYMFONY_ENV=$ENV COMPOSER_MEMORY_LIMIT=-1 composer install -n --no-dev
-cd $TMP_FOLDER/$RELEASE_FOLDER/$VERSION && php bin/console wallabag:install --env=$ENV -n
-cd $TMP_FOLDER/$RELEASE_FOLDER/$VERSION && php bin/console assets:install --env=$ENV --symlink --relative
-cd $TMP_FOLDER/$RELEASE_FOLDER && tar czf wallabag-$VERSION.tar.gz --exclude="var/cache/*" --exclude="var/logs/*" --exclude="var/sessions/*" --exclude=".git" $VERSION
+rm -rf "${TMP_FOLDER:?}"/"$RELEASE_FOLDER"
+mkdir "$TMP_FOLDER"/"$RELEASE_FOLDER"
+git clone git@github.com:wallabag/wallabag.git "$TMP_FOLDER"/"$RELEASE_FOLDER"/"$VERSION"
+cd "$TMP_FOLDER"/"$RELEASE_FOLDER"/"$VERSION" && SYMFONY_ENV="$ENV" COMPOSER_MEMORY_LIMIT=-1 composer install -n --no-dev
+cd "$TMP_FOLDER"/"$RELEASE_FOLDER"/"$VERSION" && php bin/console wallabag:install --env="$ENV" -n
+cd "$TMP_FOLDER"/"$RELEASE_FOLDER"/"$VERSION" && php bin/console assets:install --env="$ENV" --symlink --relative
+cd "$TMP_FOLDER"/"$RELEASE_FOLDER" && tar czf wallabag-"$VERSION".tar.gz --exclude="var/cache/*" --exclude="var/logs/*" --exclude="var/sessions/*" --exclude=".git" "$VERSION"
 echo "MD5 checksum of the package for wallabag $VERSION"
-md5 $TMP_FOLDER/$RELEASE_FOLDER/wallabag-$VERSION.tar.gz
+md5 "$TMP_FOLDER"/"$RELEASE_FOLDER"/wallabag-"$VERSION".tar.gz
 echo "Package to upload to the release server:"
-echo $TMP_FOLDER/$RELEASE_FOLDER/wallabag-$VERSION.tar.gz
+echo "$TMP_FOLDER"/"$RELEASE_FOLDER"/wallabag-"$VERSION".tar.gz