diff --git a/mix.exs b/mix.exs
index 901eaec86..2d5486b2d 100644
--- a/mix.exs
+++ b/mix.exs
@@ -47,6 +47,7 @@ defmodule Plausible.MixProject do
       {:phoenix_pubsub, "~> 1.1"},
       {:plug_cowboy, "~> 2.0"},
       {:postgrex, ">= 0.0.0"},
+      {:poison, "~> 3.1"}, # Used in paddle_api
       {:ref_inspector, "~> 1.3"},
       {:timex, "~> 3.6"},
       {:ua_inspector, "~> 0.18"},