diff --git a/mote/v1/openwrt/package/flukso/src/data.lua b/mote/v1/openwrt/package/flukso/src/data.lua
index 8bee82d..6fa088c 100644
--- a/mote/v1/openwrt/package/flukso/src/data.lua
+++ b/mote/v1/openwrt/package/flukso/src/data.lua
@@ -80,10 +80,10 @@ function fill(M)
   for meter, T in pairs(M) do
     local H = timestamps(T)
     for i = H[#H]-1, H[1]+1, -1 do
-      if T[i] == nil or T[i] == 'nan' then T[i] = T[i+1] end
+      if T[i] == nil or T[i] == '"nan"' then T[i] = T[i+1] end
     end
     for i = H[#H]+1, os.time() do
-      T[i] = 'nan'
+      T[i] = '"nan"'
     end
   end
 end