diff --git a/bootstrap/command/pr b/bootstrap/command/pr
index 589840a..ce3c43a 100755
--- a/bootstrap/command/pr
+++ b/bootstrap/command/pr
@@ -14,9 +14,9 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-if [[ $# == 1 ]]; then
+if [ "$#" = "1" ]; then
   git pull origin pull/$1/head
-elif [[ $# == 2 ]]; then
+elif [ "$#" = "2" ]; then
   git fetch origin pull/$1/head:$2
 else
   echo "Usage: bacardi pr <pull_request_number> [optional: branch_name]"