diff --git a/guides/intro.livemd b/guides/intro.livemd
index 5fcac5b..bf387f4 100644
--- a/guides/intro.livemd
+++ b/guides/intro.livemd
@@ -174,7 +174,7 @@ end
 
 batch_insert = fn heartbeats ->
   heartbeats
-  |> Enum.chunk_every(100)
+  |> Stream.chunk_every(div(65535, 2)) # `hartbeats` has 2 fields
   |> Enum.map(fn chunk ->
     Repo.insert_all("heartbeats", chunk)
   end)