diff --git a/docs/Migration_guide.md b/docs/Migration_guide.md
index 4283012..e50d09d 100644
--- a/docs/Migration_guide.md
+++ b/docs/Migration_guide.md
@@ -16,6 +16,7 @@ For more information on the improvements and additions please refer to the [clas
 * [Client](#client-api)
     * [Remote Services](#remote-services)
     * [Remote characteristics](#remote-characteristics)
+    * [Client Callbacks](#client-callbacks)
     * [Security](#client-security)
 * [Scanning](#scan-api)
 * [General Security](#security-api)
@@ -316,6 +317,13 @@ the currently known database returned (false : default).
 Also now returns a pointer to `std::vector` instead of `std::map`.
 <br/>
 
+<a name="client-callbacks"></a>
+### Client callbacks
+
+> `BLEClientCallbacks::onDisconnect` (`NimBLEClientCallbacks::onDisconnect`)
+
+This now takes a second parameter `int reason` which provides the reason code for disconnection.
+
 <a name="client-security"></a>
 ### Client Security
 The client will automatically initiate security when the peripheral responds that it's required.
diff --git a/examples/Bluetooth_5/NimBLE_extended_client/main/main.cpp b/examples/Bluetooth_5/NimBLE_extended_client/main/main.cpp
index 4b37285..30baeb5 100644
--- a/examples/Bluetooth_5/NimBLE_extended_client/main/main.cpp
+++ b/examples/Bluetooth_5/NimBLE_extended_client/main/main.cpp
@@ -29,8 +29,9 @@ class ClientCallbacks : public NimBLEClientCallbacks {
         printf("Connected\n");
     };
 
-    void onDisconnect(NimBLEClient* pClient) {
-        printf("%s Disconnected - Starting scan\n", pClient->getPeerAddress().toString().c_str());
+    void onDisconnect(NimBLEClient* pClient, int reason) {
+        printf("%s Disconnected, reason = %d - Starting scan\n",
+                      pClient->getPeerAddress().toString().c_str(), reason);
         NimBLEDevice::getScan()->start(scanTime, scanEndedCB);
     };
 };
diff --git a/examples/basic/BLE_client/main/main.cpp b/examples/basic/BLE_client/main/main.cpp
index 26862c1..f092bca 100644
--- a/examples/basic/BLE_client/main/main.cpp
+++ b/examples/basic/BLE_client/main/main.cpp
@@ -43,7 +43,9 @@ class MyClientCallback : public BLEClientCallbacks {
   void onConnect(BLEClient* pclient) {
   }
 
-  void onDisconnect(BLEClient* pclient) {
+  /** onDisconnect now takes a reason parameter to indicate the reason for disconnection
+  void onDisconnect(BLEClient* pclient) { */
+  void onDisconnect(BLEClient* pclient, int reason) {
     connected = false;
     printf("onDisconnect");
   }
diff --git a/src/NimBLEClient.cpp b/src/NimBLEClient.cpp
index 2899323..ecb5452 100644
--- a/src/NimBLEClient.cpp
+++ b/src/NimBLEClient.cpp
@@ -973,7 +973,7 @@ int NimBLEClient::handleGapEvent(struct ble_gap_event *event, void *arg) {
                         rc, NimBLEUtils::returnCodeToString(rc));
 
             client->m_connEstablished = false;
-            client->m_pClientCallbacks->onDisconnect(client);
+            client->m_pClientCallbacks->onDisconnect(client, rc);
             break;
         } // BLE_GAP_EVENT_DISCONNECT
 
@@ -1248,7 +1248,7 @@ void NimBLEClientCallbacks::onConnect(NimBLEClient* pClient) {
     NIMBLE_LOGD("NimBLEClientCallbacks", "onConnect: default");
 }
 
-void NimBLEClientCallbacks::onDisconnect(NimBLEClient* pClient) {
+void NimBLEClientCallbacks::onDisconnect(NimBLEClient* pClient, int reason) {
     NIMBLE_LOGD("NimBLEClientCallbacks", "onDisconnect: default");
 }
 
@@ -1261,15 +1261,7 @@ uint32_t NimBLEClientCallbacks::onPassKeyRequest(){
     NIMBLE_LOGD("NimBLEClientCallbacks", "onPassKeyRequest: default: 123456");
     return 123456;
 }
-/*
-void NimBLEClientCallbacks::onPassKeyNotify(uint32_t pass_key){
-    NIMBLE_LOGD("NimBLEClientCallbacks", "onPassKeyNotify: default: %d", pass_key);
-}
 
-bool NimBLEClientCallbacks::onSecurityRequest(){
-    NIMBLE_LOGD("NimBLEClientCallbacks", "onSecurityRequest: default: true");
-    return true;
-}*/
 void NimBLEClientCallbacks::onAuthenticationComplete(ble_gap_conn_desc* desc){
     NIMBLE_LOGD("NimBLEClientCallbacks", "onAuthenticationComplete: default");
 }
diff --git a/src/NimBLEClient.h b/src/NimBLEClient.h
index d4e349d..91766cb 100644
--- a/src/NimBLEClient.h
+++ b/src/NimBLEClient.h
@@ -131,7 +131,7 @@ public:
      * @brief Called when disconnected from the server.
      * @param [in] pClient A pointer to the calling client object.
      */
-    virtual void onDisconnect(NimBLEClient* pClient);
+    virtual void onDisconnect(NimBLEClient* pClient, int reason);
 
     /**
      * @brief Called when server requests to update the connection parameters.
@@ -147,9 +147,6 @@ public:
      */
     virtual uint32_t onPassKeyRequest();
 
-    /*virtual void onPassKeyNotify(uint32_t pass_key);
-    virtual bool onSecurityRequest();*/
-
     /**
      * @brief Called when the pairing procedure is complete.
      * @param [in] desc A pointer to the struct containing the connection information.\n
diff --git a/src/NimBLEDevice.cpp b/src/NimBLEDevice.cpp
index 6563944..ed9eb6d 100644
--- a/src/NimBLEDevice.cpp
+++ b/src/NimBLEDevice.cpp
@@ -253,7 +253,7 @@ bool NimBLEDevice::deleteClient(NimBLEClient* pClient) {
         }
         // Since we set the flag to false the app will not get a callback
         // in the disconnect event so we call it here for good measure.
-        pClient->m_pClientCallbacks->onDisconnect(pClient);
+        pClient->m_pClientCallbacks->onDisconnect(pClient, BLE_ERR_CONN_TERM_LOCAL);
 
     } else if(pClient->m_pTaskData != nullptr) {
         rc = ble_gap_conn_cancel();