diff --git a/src/USBHost/USBDeviceConnected.h b/src/USBHost/USBDeviceConnected.h
index 30d3362..8d317ca 100644
--- a/src/USBHost/USBDeviceConnected.h
+++ b/src/USBHost/USBDeviceConnected.h
@@ -21,8 +21,7 @@
 #include "USBHost/USBEndpoint.h"
 #include "USBHost/USBHostConf.h"
 #include "rtos.h"
-#undef MBED_CONF_PLATFORM_CALLBACK_NONTRIVIAL
-#define MBED_CONF_PLATFORM_CALLBACK_NONTRIVIAL  0
+#include "mbed_config.h"
 #include "Callback.h"
 
 class USBHostHub;
diff --git a/src/USBHost/USBEndpoint.h b/src/USBHost/USBEndpoint.h
index d254d0d..c85004a 100644
--- a/src/USBHost/USBEndpoint.h
+++ b/src/USBHost/USBEndpoint.h
@@ -17,8 +17,7 @@
 #ifndef USBENDPOINT_H
 #define USBENDPOINT_H
 
-#undef MBED_CONF_PLATFORM_CALLBACK_NONTRIVIAL
-#define MBED_CONF_PLATFORM_CALLBACK_NONTRIVIAL  0
+#include "mbed_config.h"
 #include "Callback.h"
 #include "USBHostTypes.h"
 #include "rtos.h"
diff --git a/src/USBHost/USBHostConf.h b/src/USBHost/USBHostConf.h
index e28640a..7145219 100644
--- a/src/USBHost/USBHostConf.h
+++ b/src/USBHost/USBHostConf.h
@@ -17,8 +17,7 @@
 #ifndef USBHOST_CONF_H
 #define USBHOST_CONF_H
 
-#undef MBED_CONF_PLATFORM_CALLBACK_NONTRIVIAL
-#define MBED_CONF_PLATFORM_CALLBACK_NONTRIVIAL  0
+#include "mbed_config.h"
 #include "Callback.h"
 #include "Arduino.h"
 
diff --git a/src/USBHostSerial/USBHostSerial.h b/src/USBHostSerial/USBHostSerial.h
index eef193e..e663cfa 100644
--- a/src/USBHostSerial/USBHostSerial.h
+++ b/src/USBHostSerial/USBHostSerial.h
@@ -24,6 +24,7 @@
 #include "USBHost/USBHost.h"
 #include "Stream.h"
 #include "MtxCircBuffer.h"
+#include "mbed_config.h"
 #include "Callback.h"
 
 /**