diff --git a/update.sh b/update.sh
index cf7e52b..44ce796 100644
--- a/update.sh
+++ b/update.sh
@@ -126,7 +126,7 @@ elif [ "${OS}" == "CentOS" ]; then
         if [ "${VM}" == "true" ]; then
            dnf install -y open-vm-tools
         fi
-        if [ -f "/opt/pbis/share/pbis.pp" ]; then
+        if [[ -f "/opt/pbis/share/pbis.pp" ]]; then
             # https://github.com/BeyondTrust/pbis-open/issues/242
             cp /opt/pbis/share/rhel/8.0/pbis.pp /opt/pbis/share/