diff --git a/api/apibasic/errorcode.cpp b/api/apibasic/errorcode.cpp
index e56c833..8b09856 100644
--- a/api/apibasic/errorcode.cpp
+++ b/api/apibasic/errorcode.cpp
@@ -91,9 +91,9 @@ const char* error2str(int32_t code) {
     ERR2STR(kstep_motor_not_enable);
     ERR2STR(kstep_motor_ioindex_out_of_range);
     ERR2STR(kmini_servo_not_enable);
-
+    ERR2STR(kmini_servo_mode_not_support);
     default:
-      return "known";
+      return "uknown";
       break;
   }
 }