diff --git a/CHANGELOG.md b/CHANGELOG.md
index 16b21f5..32a2d5b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -11,6 +11,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - Index out of range during negotiation (Grivus). [#143](https://github.com/passepartoutvpn/tunnelkit/pull/143)
 - Handle server shutdown/restart (remote `--explicit-exit-notify`). [#131](https://github.com/passepartoutvpn/tunnelkit/issues/131)
+- Pointer warnings from Xcode 11.4 upgrade.
 
 ## 2.2.1 (2019-12-14)
 
diff --git a/TunnelKit/Sources/Core/Data+Manipulation.swift b/TunnelKit/Sources/Core/Data+Manipulation.swift
index 3c0c6de..ec6d614 100644
--- a/TunnelKit/Sources/Core/Data+Manipulation.swift
+++ b/TunnelKit/Sources/Core/Data+Manipulation.swift
@@ -85,19 +85,25 @@ extension Data {
 extension Data {
     mutating func append(_ value: UInt16) {
         var localValue = value
-        let buffer = UnsafeBufferPointer(start: &localValue, count: 1)
+        let buffer = withUnsafePointer(to: &localValue) {
+            return UnsafeBufferPointer(start: $0, count: 1)
+        }
         append(buffer)
     }
     
     mutating func append(_ value: UInt32) {
         var localValue = value
-        let buffer = UnsafeBufferPointer(start: &localValue, count: 1)
+        let buffer = withUnsafePointer(to: &localValue) {
+            return UnsafeBufferPointer(start: $0, count: 1)
+        }
         append(buffer)
     }
     
     mutating func append(_ value: UInt64) {
         var localValue = value
-        let buffer = UnsafeBufferPointer(start: &localValue, count: 1)
+        let buffer = withUnsafePointer(to: &localValue) {
+            return UnsafeBufferPointer(start: $0, count: 1)
+        }
         append(buffer)
     }
     
diff --git a/TunnelKitTests/OpenVPN/EncryptionPerformanceTests.swift b/TunnelKitTests/OpenVPN/EncryptionPerformanceTests.swift
index 4897441..c0b2f39 100644
--- a/TunnelKitTests/OpenVPN/EncryptionPerformanceTests.swift
+++ b/TunnelKitTests/OpenVPN/EncryptionPerformanceTests.swift
@@ -81,7 +81,9 @@ class EncryptionPerformanceTests: XCTestCase {
     func testGCMEncryption() {
         let suite = TestUtils.generateDataSuite(1000, 100000)
         let ad: [UInt8] = [0x11, 0x22, 0x33, 0x44]
-        var flags = CryptoFlags(iv: nil, ivLength: 0, ad: ad, adLength: ad.count)
+        var flags = ad.withUnsafeBufferPointer {
+            return CryptoFlags(iv: nil, ivLength: 0, ad: $0.baseAddress, adLength: ad.count)
+        }
         measure {
             for data in suite {
                 let _ = try! self.gcmEncrypter.encryptData(data, flags: &flags)
diff --git a/TunnelKitTests/OpenVPN/EncryptionTests.swift b/TunnelKitTests/OpenVPN/EncryptionTests.swift
index f877d71..e5fd24f 100644
--- a/TunnelKitTests/OpenVPN/EncryptionTests.swift
+++ b/TunnelKitTests/OpenVPN/EncryptionTests.swift
@@ -81,7 +81,11 @@ class EncryptionTests: XCTestCase {
         
         let packetId: [UInt8] = [0x56, 0x34, 0x12, 0x00]
         let ad: [UInt8] = [0x00, 0x12, 0x34, 0x56]
-        var flags = CryptoFlags(iv: packetId, ivLength: packetId.count, ad: ad, adLength: ad.count)
+        var flags = packetId.withUnsafeBufferPointer { (iv) in
+            return ad.withUnsafeBufferPointer { (ad) in
+                return CryptoFlags(iv: iv.baseAddress, ivLength: packetId.count, ad: ad.baseAddress, adLength: ad.count)
+            }
+        }
         let plain = Data(hex: "00112233445566778899")
         let encrypted = try! client.encrypter().encryptData(plain, flags: &flags)
         let decrypted = try! server.decrypter().decryptData(encrypted, flags: &flags)
@@ -93,7 +97,9 @@ class EncryptionTests: XCTestCase {
 
         let original = Data(hex: "0000000000")
         let ad: [UInt8] = [UInt8](Data(hex: "38afa8f1162096081e000000015ba35373"))
-        var flags = CryptoFlags(iv: nil, ivLength: 0, ad: ad, adLength: ad.count)
+        var flags = ad.withUnsafeBufferPointer {
+            CryptoFlags(iv: nil, ivLength: 0, ad: $0.baseAddress, adLength: ad.count)
+        }
 
 //        let expEncrypted = Data(hex: "319bb8e7f8f7930cc4625079dd32a6ef9540c2fc001c53f909f712037ae9818af840b88714")
         let encrypted = try! client.encrypter().encryptData(original, flags: &flags)