diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 9e53f5e..2ce03df 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -11,13 +11,15 @@ jobs:
       matrix:
         include:
           - elixir: '1.16'
-            otp: '26.2.5'
+            erlang: '26.2.5'
             lint: true
+          - elixir: '1.15'
+            erlang: '25.3.2.12'
     steps:
       - uses: actions/checkout@v4
       - uses: erlef/setup-beam@v1
         with:
-          otp-version: ${{ matrix.otp }}
+          otp-version: ${{ matrix.erlang }}
           elixir-version: ${{ matrix.elixir }}
       - run: mix deps.get --check-locked
       - run: mix format --check-formatted
diff --git a/mix.exs b/mix.exs
index f60ad55..6de0dfc 100644
--- a/mix.exs
+++ b/mix.exs
@@ -10,7 +10,7 @@ defmodule Tower.MixProject do
       app: :tower,
       description: @description,
       version: @version,
-      elixir: "~> 1.16",
+      elixir: "~> 1.15",
       start_permanent: Mix.env() == :prod,
       deps: deps(),
       package: package(),