diff --git a/src/device/usbd.c b/src/device/usbd.c
index a3f9126de..f638eb619 100644
--- a/src/device/usbd.c
+++ b/src/device/usbd.c
@@ -56,6 +56,10 @@ TU_ATTR_WEAK void tud_event_hook_cb(uint8_t rhport, uint32_t eventid, bool in_is
   (void)in_isr;
 }
 
+TU_ATTR_WEAK void tud_sof_cb(uint32_t frame_count) {
+  (void)frame_count;
+}
+
 //--------------------------------------------------------------------+
 // Device Data
 //--------------------------------------------------------------------+
@@ -637,7 +641,7 @@ void tud_task_ext(uint32_t timeout_ms, bool in_isr) {
         if ( _usbd_sof.cb_en)
         {
           TU_LOG_USBD("\r\n");
-          if ( tud_sof_cb ) tud_sof_cb(event.sof.frame_count);
+          tud_sof_cb(event.sof.frame_count);
         }
       break;
 
diff --git a/src/device/usbd.h b/src/device/usbd.h
index ee83ddc32..cba94fdae 100644
--- a/src/device/usbd.h
+++ b/src/device/usbd.h
@@ -156,7 +156,7 @@ TU_ATTR_WEAK void tud_resume_cb(void);
 void tud_event_hook_cb(uint8_t rhport, uint32_t eventid, bool in_isr);
 
 // Invoked when a new (micro) frame started
-TU_ATTR_WEAK void tud_sof_cb(uint32_t frame_count);
+void tud_sof_cb(uint32_t frame_count);
 
 // Invoked when received control request with VENDOR TYPE
 TU_ATTR_WEAK bool tud_vendor_control_xfer_cb(uint8_t rhport, uint8_t stage, tusb_control_request_t const * request);