diff --git a/openwrt/package/flukso/src/flukso.lua b/openwrt/package/flukso/src/flukso.lua
index 93bc20b..339ac1c 100755
--- a/openwrt/package/flukso/src/flukso.lua
+++ b/openwrt/package/flukso/src/flukso.lua
@@ -78,14 +78,16 @@ function buffer(child, interval)
   return coroutine.create(function(meter, timestamp, value)
     local measurements = data.new()
     local threshold = timestamp + interval
-    local old_timestamp = 0
+    local timestamp_prev = {}
 
     while true do
-      if meter ~= nil and timestamp > math.max(1234567890, old_timestamp) then measurements:add(meter, timestamp, value) end
+      if meter ~= nil and timestamp > math.max(1234567890, timestamp_prev[meter] or 0) then
+        measurements:add(meter, timestamp, value)
+      end
       if timestamp > threshold and next(measurements) then  --checking whether table is not empty
         coroutine.resume(child, measurements)
         threshold = timestamp + interval
-        old_timestamp = timestamp
+        timestamp_prev[meter] = timestamp
       end
       meter, timestamp, value = coroutine.yield()
     end