diff --git a/.github/workflows/elixir.yml b/.github/workflows/elixir.yml
index a378797..491c9ea 100644
--- a/.github/workflows/elixir.yml
+++ b/.github/workflows/elixir.yml
@@ -11,7 +11,7 @@ jobs:
     strategy:
       matrix:
         otp: ['24', '25']
-        elixir-version: ['1.13', '1.14']
+        elixir-version: ['1.14', '1.15']
     services:
       postgres:
         image: postgres:15-alpine
diff --git a/Dockerfile b/Dockerfile
index d4c0918..2af2d9b 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,4 @@
-FROM elixir:1.14.5-alpine AS build
+FROM elixir:1.15.0-alpine AS build
 # install build dependencies
 RUN apk add --no-cache build-base npm git python3
 # prepare build dir
diff --git a/config/releases.exs b/config/releases.exs
index 77e23d9..84714c2 100644
--- a/config/releases.exs
+++ b/config/releases.exs
@@ -25,7 +25,7 @@ secret_key_base =
 
 host_name =
   if System.get_env("APP_NAME"),
-    do: System.get_env("APP_NAME") <> 'gigalixirapp.com',
+    do: System.get_env("APP_NAME") <> ~c"gigalixirapp.com",
     else: System.get_env("HOSTNAME")
 
 config :elixir_exploration, ElixirExplorationWeb.Endpoint,
diff --git a/mix.exs b/mix.exs
index c71650b..5c7479e 100644
--- a/mix.exs
+++ b/mix.exs
@@ -72,7 +72,9 @@ defmodule ElixirExploration.MixProject do
       {:sobelow, "~> 0.11", only: :dev},
       {:mimic, "~> 1.7.1", only: :test},
       {:oauther, "~> 1.3"},
-      {:extwitter, "~> 0.13"}
+      {:extwitter, "~> 0.13"},
+      {:ssl_verify_fun, "~> 1.1.6",
+       manager: :rebar3, only: [:test], runtime: false, override: true}
     ]
   end