diff --git a/Marlin/src/lcd/extui/lib/mks_ui/tft_lvgl_configuration.cpp b/Marlin/src/lcd/extui/lib/mks_ui/tft_lvgl_configuration.cpp
index b7441f71f4c3..2c0a57cf2d01 100644
--- a/Marlin/src/lcd/extui/lib/mks_ui/tft_lvgl_configuration.cpp
+++ b/Marlin/src/lcd/extui/lib/mks_ui/tft_lvgl_configuration.cpp
@@ -369,6 +369,7 @@ lv_fs_res_t spi_flash_tell_cb(lv_fs_drv_t * drv, void * file_p, uint32_t * pos_p
 }
 
 //sd
+extern uint8_t public_buf[512];
 char *cur_namefff;
 uint32_t sd_read_base_addr = 0, sd_read_addr_offset = 0, small_image_size = 409;
 lv_fs_res_t sd_open_cb (lv_fs_drv_t * drv, void * file_p, const char * path, lv_fs_mode_t mode) {