diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8c1e89e..9f64bb2 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,12 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## Unreleased
+
+### Fixed
+
+- Send explicit exit notification if UDP. [#29](https://github.com/keeshux/tunnelkit/issues/29)
+
 ## 1.5.0 (2019-03-20)
 
 ### Added
diff --git a/TunnelKit/Sources/Core/Packet.swift b/TunnelKit/Sources/Core/Packet.swift
index 036f5fb..b934f61 100644
--- a/TunnelKit/Sources/Core/Packet.swift
+++ b/TunnelKit/Sources/Core/Packet.swift
@@ -128,6 +128,22 @@ class DataPacket {
     static let pingString = Data(hex: "2a187bf3641eb4cb07ed2d0a981fc748")
 }
 
+enum OCCPacket: UInt8 {
+    case exit = 0x06
+    
+    private static let magicString = Data(hex: "287f346bd4ef7a812d56b8d3afc5459c")
+
+    func serialized(_ info: Any? = nil) -> Data {
+        var data = OCCPacket.magicString
+        data.append(rawValue)
+        switch self {
+        case .exit:
+            break // nothing more
+        }
+        return data
+    }
+}
+
 /// :nodoc:
 extension PacketCode: CustomStringConvertible {
     public var description: String {
diff --git a/TunnelKit/Sources/Core/SessionProxy.swift b/TunnelKit/Sources/Core/SessionProxy.swift
index 366daa0..da820b6 100644
--- a/TunnelKit/Sources/Core/SessionProxy.swift
+++ b/TunnelKit/Sources/Core/SessionProxy.swift
@@ -992,8 +992,8 @@ public class SessionProxy {
                 self?.queue.sync {
                     log.error("Failed LINK write during control flush: \(error)")
                     self?.deferStop(.shutdown, SessionError.failedLinkWrite)
-                    return
                 }
+                return
             }
         }
     }
@@ -1115,8 +1115,8 @@ public class SessionProxy {
                     self?.queue.sync {
                         log.error("Data: Failed LINK write during send data: \(error)")
                         self?.deferStop(.shutdown, SessionError.failedLinkWrite)
-                        return
                     }
+                    return
                 }
 //                log.verbose("Data: \(encryptedPackets.count) packets successfully written to LINK")
             }
@@ -1161,8 +1161,8 @@ public class SessionProxy {
                 self?.queue.sync {
                     log.error("Failed LINK write during send ack for packetId \(controlPacket.packetId): \(error)")
                     self?.deferStop(.shutdown, SessionError.failedLinkWrite)
-                    return
                 }
+                return
             }
             log.debug("Ack successfully written to LINK for packetId \(controlPacket.packetId)")
         }
@@ -1176,13 +1176,32 @@ public class SessionProxy {
     
     private func deferStop(_ method: StopMethod, _ error: Error?) {
         isStopping = true
-        
-        switch method {
-        case .shutdown:
-            doShutdown(error: error)
-        
-        case .reconnect:
-            doReconnect(error: error)
+
+        let completion = { [weak self] in
+            switch method {
+            case .shutdown:
+                self?.doShutdown(error: error)
+                
+            case .reconnect:
+                self?.doReconnect(error: error)
+            }
+        }
+
+        // shut down after sending exit notification if socket is unreliable (normally UDP)
+        if let link = link, !link.isReliable {
+            do {
+                guard let packets = try currentKey?.encrypt(packets: [OCCPacket.exit.serialized()]) else {
+                    completion()
+                    return
+                }
+                link.writePackets(packets) { (error) in
+                    completion()
+                }
+            } catch {
+                completion()
+            }
+        } else {
+            completion()
         }
     }