diff --git a/init.lua b/init.lua
index 578dfb1..c729021 100644
--- a/init.lua
+++ b/init.lua
@@ -66,16 +66,14 @@ end
 -- GET /sync
 function MatrixChat:get_sync_table(timeout)
     local params = {}
-    -- no filter param
     if self.since ~= nil then
-        params[1] = "since=" .. self.since
+        table.insert(params, "since=" .. self.since)
     end
     if timeout ~= nil then
-        -- if timeout is defined and since took the starting '?'
-        params[2] =  "timeout=" .. timeout
+        table.insert(params, "timeout=" .. timeout)
     end
     local u = self.server .."/_matrix/client/r0/sync"
-    if params[1] ~= nil then
+    if #params > 0 then
         u = u .. "?" .. table.concat(params, "&")
     end
     local h = {"Authorization: Bearer " .. self.token}