diff --git a/lib/pleroma/webhook/notify.ex b/lib/pleroma/webhook/notify.ex
index 7dbfc52a0..743bb4012 100644
--- a/lib/pleroma/webhook/notify.ex
+++ b/lib/pleroma/webhook/notify.ex
@@ -78,6 +78,6 @@ defmodule Pleroma.Webhook.Notify do
   end
 
   defp signature(body, secret) do
-    :crypto.mac(:hmac, :sha256, secret, body) |> Base.encode16()
+    :crypto.mac(:hmac, :sha256, secret, body) |> Base.encode16(case: :lower)
   end
 end
diff --git a/test/pleroma/webhook/notify_test.exs b/test/pleroma/webhook/notify_test.exs
index e03890aab..c99489940 100644
--- a/test/pleroma/webhook/notify_test.exs
+++ b/test/pleroma/webhook/notify_test.exs
@@ -66,7 +66,7 @@ defmodule Pleroma.Webhook.NotifyTest do
       {"X-Hub-Signature", "sha256=" <> signature} =
         Enum.find(headers, fn {key, _} -> key == "X-Hub-Signature" end)
 
-      assert signature == :crypto.mac(:hmac, :sha256, secret, body) |> Base.encode16()
+      assert signature == :crypto.mac(:hmac, :sha256, secret, body) |> Base.encode16(case: :lower)
       %Tesla.Env{status: 200, body: ""}
     end)