diff --git a/features/FEATURE_BLE/ble/GattClient.h b/features/FEATURE_BLE/ble/GattClient.h
index 5eff0df04e..828536ffbd 100644
--- a/features/FEATURE_BLE/ble/GattClient.h
+++ b/features/FEATURE_BLE/ble/GattClient.h
@@ -112,7 +112,7 @@ public:
      */
     void setEventHandler(EventHandler *handler)
     {
-        _eventHandler = handler;
+        eventHandler = handler;
     }
 
     /**
@@ -795,7 +795,7 @@ public:
     }
 
 protected:
-    GattClient()
+    GattClient() : eventHandler(NULL)
     {
         /* Empty */
     }
@@ -850,7 +850,7 @@ protected:
     /**
      * Event handler provided by the application.
      */
-    EventHandler *_eventHandler;
+    EventHandler *eventHandler;
 
     /**
      * Callchain containing all registered event handlers for data read
diff --git a/features/FEATURE_BLE/ble/GattServer.h b/features/FEATURE_BLE/ble/GattServer.h
index 8335e7f798..2a1bf417ce 100644
--- a/features/FEATURE_BLE/ble/GattServer.h
+++ b/features/FEATURE_BLE/ble/GattServer.h
@@ -116,7 +116,7 @@ public:
      */
     void setEventHandler(EventHandler *handler)
     {
-        _eventHandler = handler;
+        eventHandler = handler;
     }
 
     /**
@@ -198,6 +198,7 @@ protected:
     GattServer() :
         serviceCount(0),
         characteristicCount(0),
+        eventHandler(NULL),
         dataSentCallChain(),
         dataWrittenCallChain(),
         dataReadCallChain(),
@@ -813,7 +814,7 @@ protected:
     /**
      * Event handler provided by the application.
      */
-    EventHandler *_eventHandler;
+    EventHandler *eventHandler;
 
     /**
      * The total number of services added to the ATT table.
diff --git a/features/FEATURE_BLE/ble/generic/GenericGattClient.h b/features/FEATURE_BLE/ble/generic/GenericGattClient.h
index eece4dfed4..3759e8f1bd 100644
--- a/features/FEATURE_BLE/ble/generic/GenericGattClient.h
+++ b/features/FEATURE_BLE/ble/generic/GenericGattClient.h
@@ -37,13 +37,16 @@ class GenericGattClient : public GattClient,
                           public pal::GattClient::EventHandler {
 public:
 
+    /**
+     * @see pal::GattClient::EventHandler::on_att_mtu_change
+     */
     virtual void on_att_mtu_change(
         ble::connection_handle_t connection_handle,
         uint16_t att_mtu_size
     )
     {
-        if (_eventHandler) {
-            _eventHandler->onAttMtuChange(connection_handle, att_mtu_size);
+        if (eventHandler) {
+            eventHandler->onAttMtuChange(connection_handle, att_mtu_size);
         }
     }
 
@@ -140,8 +143,12 @@ public:
      */
     virtual void set_signing_event_handler(pal::SigningEventMonitor::EventHandler *signing_event_handler);
 
+    /**
+     *  Return the user registered event handler.
+     * @return User registered event handler or NULL if none is present.
+     */
     ::GattClient::EventHandler* getEventHandler() {
-        return _eventHandler;
+        return eventHandler;
     }
 
 private:
diff --git a/features/FEATURE_BLE/targets/TARGET_CORDIO/CordioGattServer.h b/features/FEATURE_BLE/targets/TARGET_CORDIO/CordioGattServer.h
index 84dc2dbdf0..4979ce6249 100644
--- a/features/FEATURE_BLE/targets/TARGET_CORDIO/CordioGattServer.h
+++ b/features/FEATURE_BLE/targets/TARGET_CORDIO/CordioGattServer.h
@@ -63,7 +63,7 @@ public:
     static GattServer &getInstance();
 
     ::GattServer::EventHandler* getEventHandler() {
-        return _eventHandler;
+        return eventHandler;
     }
 
     /**
diff --git a/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_NORDIC_SOFTDEVICE/TARGET_MCU_NRF51822/source/nRF5xGattServer.h b/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_NORDIC_SOFTDEVICE/TARGET_MCU_NRF51822/source/nRF5xGattServer.h
index a115d24775..7cd58b1cf4 100644
--- a/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_NORDIC_SOFTDEVICE/TARGET_MCU_NRF51822/source/nRF5xGattServer.h
+++ b/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_NORDIC_SOFTDEVICE/TARGET_MCU_NRF51822/source/nRF5xGattServer.h
@@ -42,7 +42,7 @@ public:
     void hwCallback(ble_evt_t *p_ble_evt);
 
     EventHandler* getEventHandler() {
-        return _eventHandler;
+        return eventHandler;
     }
 
 private:
diff --git a/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_NORDIC_SOFTDEVICE/TARGET_NRF51/source/nRF5xGattServer.h b/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_NORDIC_SOFTDEVICE/TARGET_NRF51/source/nRF5xGattServer.h
index baedd6473d..8069c8c5e9 100644
--- a/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_NORDIC_SOFTDEVICE/TARGET_NRF51/source/nRF5xGattServer.h
+++ b/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_NORDIC_SOFTDEVICE/TARGET_NRF51/source/nRF5xGattServer.h
@@ -42,7 +42,7 @@ public:
     void hwCallback(const ble_evt_t *p_ble_evt);
 
     EventHandler* getEventHandler() {
-        return _eventHandler;
+        return eventHandler;
     }
 
 private:
diff --git a/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_NORDIC_SOFTDEVICE/TARGET_NRF52/source/nRF5xGattServer.h b/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_NORDIC_SOFTDEVICE/TARGET_NRF52/source/nRF5xGattServer.h
index 77d6f91fa5..270a211ac2 100644
--- a/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_NORDIC_SOFTDEVICE/TARGET_NRF52/source/nRF5xGattServer.h
+++ b/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_NORDIC_SOFTDEVICE/TARGET_NRF52/source/nRF5xGattServer.h
@@ -42,7 +42,7 @@ public:
     void hwCallback(const ble_evt_t *p_ble_evt);
 
     EventHandler* getEventHandler() {
-        return _eventHandler;
+        return eventHandler;
     }
 
 private: