diff --git a/src/class/dfu/dfu_device.c b/src/class/dfu/dfu_device.c
index f3763adc7..85e884d0d 100644
--- a/src/class/dfu/dfu_device.c
+++ b/src/class/dfu/dfu_device.c
@@ -269,7 +269,7 @@ bool dfu_moded_control_xfer_cb(uint8_t rhport, uint8_t stage, tusb_control_reque
     default:
     {
       TU_LOG2("  DFU Nonstandard Request: %u\r\n", request->bRequest);
-      return ( tud_dfu_req_nonstandard_cb ) ? tud_dfu_req_nonstandard_cb(rhport, stage, request) : false;
+      return false; // stall unsupported request
     }
     break;
   }
diff --git a/src/class/dfu/dfu_device.h b/src/class/dfu/dfu_device.h
index 3bc1f4ae4..28a241b3a 100644
--- a/src/class/dfu/dfu_device.h
+++ b/src/class/dfu/dfu_device.h
@@ -107,11 +107,6 @@ TU_ATTR_WEAK void tud_dfu_abort_cb(void);
 // Return the number of bytes to write
 uint16_t tud_dfu_req_upload_data_cb(uint16_t block_num, uint8_t* data, uint16_t length);
 
-// Invoked when a nonstandard request is received
-// Use may be vendor specific.
-// Return false to stall
-TU_ATTR_WEAK bool tud_dfu_req_nonstandard_cb(uint8_t rhport, uint8_t stage, tusb_control_request_t const * request);
-
 // Invoked during a DFU_GETSTATUS request to get for the string index
 // to the status description string table.
 TU_ATTR_WEAK uint8_t tud_dfu_get_status_desc_table_index_cb(void);