diff --git a/lib/mix/tasks/deps.tree.ex b/lib/mix/tasks/deps.tree.ex
index 50189c3d2..9937270cd 100644
--- a/lib/mix/tasks/deps.tree.ex
+++ b/lib/mix/tasks/deps.tree.ex
@@ -65,7 +65,7 @@ defmodule Mix.Tasks.Ejabberd.Deps.Tree do
 
   defp keep_only_mods_not_used_as_dep(mods, mods_used_as_dep) do
     Enum.filter mods, fn %{module: mod} ->
-      mod not in mods_used_as_dep
+      not (mod in mods_used_as_dep)
     end
   end