diff --git a/WireGuard/WireGuard/Model/Configuration.swift b/WireGuard/WireGuard/Model/Configuration.swift
index ce71630..b135ddd 100644
--- a/WireGuard/WireGuard/Model/Configuration.swift
+++ b/WireGuard/WireGuard/Model/Configuration.swift
@@ -22,7 +22,7 @@ struct InterfaceConfiguration: Codable {
     var name: String
     var privateKey: Data
     var addresses: [IPAddressRange] = []
-    var listenPort: UInt64? = nil
+    var listenPort: UInt16? = nil
     var mtu: UInt64? = nil
     var dns: String? = nil
 
@@ -46,7 +46,7 @@ struct PeerConfiguration: Codable {
     }
     var allowedIPs: [IPAddressRange] = []
     var endpoint: Endpoint?
-    var persistentKeepAlive: UInt64?
+    var persistentKeepAlive: UInt16?
 
     init(publicKey: Data) {
         self.publicKey = publicKey
diff --git a/WireGuard/WireGuard/UI/TunnelViewModel.swift b/WireGuard/WireGuard/UI/TunnelViewModel.swift
index 6b6285c..13c831f 100644
--- a/WireGuard/WireGuard/UI/TunnelViewModel.swift
+++ b/WireGuard/WireGuard/UI/TunnelViewModel.swift
@@ -109,11 +109,11 @@ class TunnelViewModel {
                 config.addresses = addresses
             }
             if let listenPortString = scratchpad[.listenPort] {
-                if let listenPort = UInt64(listenPortString) {
+                if let listenPort = UInt16(listenPortString) {
                     config.listenPort = listenPort
                 } else {
                     fieldsWithError.insert(.listenPort)
-                    errorMessages.append("Interface's listen port should be a number")
+                    errorMessages.append("Interface's listen port should be a 16-bit integer (0 to 65535)")
                 }
             }
             if let mtuString = scratchpad[.mtu] {
@@ -231,11 +231,11 @@ class TunnelViewModel {
                 }
             }
             if let persistentKeepAliveString = scratchpad[.persistentKeepAlive] {
-                if let persistentKeepAlive = UInt64(persistentKeepAliveString) {
+                if let persistentKeepAlive = UInt16(persistentKeepAliveString) {
                     config.persistentKeepAlive = persistentKeepAlive
                 } else {
                     fieldsWithError.insert(.persistentKeepAlive)
-                    errorMessages.append("Peer's persistent keepalive should be a number")
+                    errorMessages.append("Peer's persistent keepalive should be a 16-bit integer (0 to 65535)")
                 }
             }