diff --git a/loader/Project/Model/Src/prj_main.c b/loader/Project/Model/Src/prj_main.c
index 348d88d3f..1dd9c1281 100755
--- a/loader/Project/Model/Src/prj_main.c
+++ b/loader/Project/Model/Src/prj_main.c
@@ -41,6 +41,14 @@
 #define GPIO_SPECIAL_KEY GPIO_KEY_TEST
 #define GPIO_SPECIAL_KEY2 GPIO_ISP_KEY_DET
 #define GPIO_SPECIAL_USB D_GPIO_7
+
+#elif (MODEL == MODEL_S550)
+#define GPIO_KEY_TEST P_GPIO_22
+#define GPIO_ISP_KEY_DET C_GPIO_4
+#define GPIO_FASTBOOT_KEY GPIO_KEY_TEST
+#define GPIO_SPECIAL_KEY GPIO_KEY_TEST
+#define GPIO_SPECIAL_KEY2 GPIO_ISP_KEY_DET
+#define GPIO_SPECIAL_USB D_GPIO_7
 /* Unknown */
 #else
 #error "Unknown Model"