diff --git a/lvgl_helpers.h b/lvgl_helpers.h
index 3e7715b..69d8ce4 100644
--- a/lvgl_helpers.h
+++ b/lvgl_helpers.h
@@ -48,7 +48,7 @@ extern "C" {
 #if defined (CONFIG_LV_TFT_DISPLAY_CONTROLLER_ST7789)
 #define DISP_BUF_SIZE  (LV_HOR_RES_MAX * 40)
 #elif defined CONFIG_LV_TFT_DISPLAY_CONTROLLER_ST7735S
-#define DISP_BUF_SIZE  (LV_HOR_RES_MAX * 40)
+#define DISP_BUF_SIZE  (LV_HOR_RES_MAX * LV_VER_RES_MAX)
 #elif defined CONFIG_LV_TFT_DISPLAY_CONTROLLER_ST7796S
 #define DISP_BUF_SIZE  (LV_HOR_RES_MAX * 40)
 #elif defined CONFIG_LV_TFT_DISPLAY_CONTROLLER_HX8357