diff --git a/drivers/USBCDC_ECM.h b/drivers/USBCDC_ECM.h
index 7b2971e7b47..db83a57474e 100644
--- a/drivers/USBCDC_ECM.h
+++ b/drivers/USBCDC_ECM.h
@@ -18,6 +18,7 @@
 #ifndef USBCDC_ECM_H
 #define USBCDC_ECM_H
 
+#if defined(MBED_CONF_RTOS_PRESENT)
 #include "USBDescriptor.h"
 #include "USBDevice.h"
 #include "ByteBuffer.h"
@@ -275,5 +276,5 @@ class USBCDC_ECM: public USBDevice {
 };
 
 /** @}*/
-
+#endif // defined(MBED_CONF_RTOS_PRESENT)
 #endif
diff --git a/drivers/source/usb/USBCDC_ECM.cpp b/drivers/source/usb/USBCDC_ECM.cpp
index 976328e2917..45e97ad1948 100644
--- a/drivers/source/usb/USBCDC_ECM.cpp
+++ b/drivers/source/usb/USBCDC_ECM.cpp
@@ -14,7 +14,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-
+#if defined(MBED_CONF_RTOS_PRESENT)
 #include <stdint.h>
 #include "USBCDC_ECM.h"
 #include "EndpointResolver.h"
@@ -556,3 +556,4 @@ void USBCDC_ECM::_bulk_out_callback()
 
     read_start(_bulk_out, _bulk_buf, MAX_PACKET_SIZE_BULK);
 }
+#endif // defined(MBED_CONF_RTOS_PRESENT)