diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index efbd066..d0d1629 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -30,9 +30,9 @@ jobs:
             otp: "22.3"
 
           # Oldest supported versions.
-          - os: ubuntu-18.04
-            elixir: "1.7.4"
-            otp: "19.3.6.13"
+          - os: ubuntu-20.04
+            elixir: "1.11"
+            otp: "21.3.8.24"
 
     steps:
       - name: Check out this repository
diff --git a/mix.exs b/mix.exs
index 6efe064..0b98788 100644
--- a/mix.exs
+++ b/mix.exs
@@ -7,7 +7,7 @@ defmodule GenStage.Mixfile do
     [
       app: :gen_stage,
       version: @version,
-      elixir: "~> 1.7",
+      elixir: "~> 1.11",
       package: package(),
       description: "Producer and consumer actors with back-pressure for Elixir",
       start_permanent: Mix.env() == :prod,