diff --git a/openvpn-install.sh b/openvpn-install.sh
index 0354bc3..8eaae90 100755
--- a/openvpn-install.sh
+++ b/openvpn-install.sh
@@ -209,7 +209,7 @@ function installQuestions() {
 
 	# Detect public IPv4 address and pre-fill for the user
 	IP=$(ip -4 addr | sed -ne 's|^.* inet \([^/]*\)/.* scope global.*$|\1|p' | head -1)
-	if [[ -z "$IP" ]]; then
+	if [[ -z $IP ]]; then
 		# Detect public IPv6 address
 		IP=$(ip -6 addr | sed -ne 's|^.* inet6 \([^/]*\)/.* scope global.*$|\1|p' | head -1)
 	fi