diff --git a/apisix/plugins/limit-count/limit-count-redis.lua b/apisix/plugins/limit-count/limit-count-redis.lua
index b71cd852b0a0..a4dfba51b36e 100644
--- a/apisix/plugins/limit-count/limit-count-redis.lua
+++ b/apisix/plugins/limit-count/limit-count-redis.lua
@@ -71,7 +71,12 @@ function _M.incoming(self, key)
     local remaining
     key = self.plugin_name .. tostring(key)
 
-    local ret = red:ttl(key)
+    -- todo: test case
+    local ret, err = red:ttl(key)
+    if not ret then
+        return false, "failed to get redis `" .. key .."` ttl: " .. err
+    end
+
     core.log.info("ttl key: ", key, " ret: ", ret, " err: ", err)
     if ret < 0 then
         -- todo: test case