diff --git a/features/FEATURE_BLE/source/GattClient.tpp b/features/FEATURE_BLE/source/GattClient.tpp
index 5d38c469e0..8f68af097e 100644
--- a/features/FEATURE_BLE/source/GattClient.tpp
+++ b/features/FEATURE_BLE/source/GattClient.tpp
@@ -186,6 +186,13 @@ void GattClient<Impl>::terminateServiceDiscovery_(void)
 {
 }
 
+template<class Impl>
+ble_error_t GattClient<Impl>::negotiateAttMtu_(
+    ble::connection_handle_t connHandle
+) {
+    return BLE_ERROR_NOT_IMPLEMENTED;
+}
+
 template<class Impl>
 ble_error_t GattClient<Impl>::read_(
     ble::connection_handle_t connHandle,