diff --git a/wireguard-install.sh b/wireguard-install.sh
index 413febf..8b0c7e3 100644
--- a/wireguard-install.sh
+++ b/wireguard-install.sh
@@ -69,11 +69,13 @@ function installWireGuard() {
 	SERVER_WG_NIC="wg0"
 	read -rp "WireGuard interface name: " -e -i "$SERVER_WG_NIC" SERVER_WG_NIC
 
-	SERVER_WG_IPV4="10.66.66.1"
-	read -rp "Server's WireGuard IPv4: " -e -i "$SERVER_WG_IPV4" SERVER_WG_IPV4
+	until [[ "$SERVER_WG_IPV4" =~ ^([0-9]{1,3}\.){3}1$ ]]; do
+		read -rp "Server's WireGuard IPv4 [x.x.x.1]: " -e -i 10.66.66.1 SERVER_WG_IPV4
+	done
 
-	SERVER_WG_IPV6="fd42:42:42::1"
-	read -rp "Server's WireGuard IPv6: " -e -i "$SERVER_WG_IPV6" SERVER_WG_IPV6
+	until [[ "$SERVER_WG_IPV6" =~ ^([a-f0-9]{1,4}:){3,4}:1$ ]]; do
+		read -rp "Server's WireGuard IPv6 [x:x:x::1]: " -e -i fd42:42:42::1 SERVER_WG_IPV6
+	done
 
 	# Generate random number within private ports range
 	RANDOM_PORT=$(shuf -i49152-65535 -n1)
@@ -186,11 +188,11 @@ function newClient() {
 	fi
 
 	until [[ "$CLIENT_WG_IPV4" =~ ^([0-9]{1,3}\.?){4}$ ]]; do
-		read -rp "Client's WireGuard IPv4: " -e -i "${SERVER_WG_IPV4: : -1}"2 CLIENT_WG_IPV4
+		read -rp "Client's WireGuard IPv4: " -e -i "${SERVER_WG_IPV4::-1}"2 CLIENT_WG_IPV4
 	done
 
 	until [[ "$CLIENT_WG_IPV6" =~ ^([a-f0-9]{1,4}:?:?){3,5} ]]; do
-		read -rp "Client's WireGuard IPv6 : " -e -i "${SERVER_WG_IPV6: : -1}"2 CLIENT_WG_IPV6
+		read -rp "Client's WireGuard IPv6 : " -e -i "${SERVER_WG_IPV6::-1}"2 CLIENT_WG_IPV6
 	done
 
 	# Adguard DNS by default