diff --git a/.changesets/fix-telemetry-local-function-warning.md b/.changesets/fix-telemetry-local-function-warning.md
new file mode 100644
index 000000000..9127430d8
--- /dev/null
+++ b/.changesets/fix-telemetry-local-function-warning.md
@@ -0,0 +1,6 @@
+---
+bump: "patch"
+type: "fix"
+---
+
+Suppress a warning emitted by Telemetry 1.0.0, regarding the performance penalty of using local functions as event handlers, by specifying the module of the captured function.
diff --git a/lib/appsignal/ecto.ex b/lib/appsignal/ecto.ex
index 216e64382..b254e745f 100644
--- a/lib/appsignal/ecto.ex
+++ b/lib/appsignal/ecto.ex
@@ -29,7 +29,7 @@ defmodule Appsignal.Ecto do
   def attach(otp_app, repo) do
     event = telemetry_prefix(otp_app, repo) ++ [:query]
 
-    case :telemetry.attach({__MODULE__, event}, event, &handle_event/4, :ok) do
+    case :telemetry.attach({__MODULE__, event}, event, &__MODULE__.handle_event/4, :ok) do
       :ok ->
         Appsignal.Logger.debug("Appsignal.Ecto attached to #{inspect(event)}")