diff --git a/.github/main.workflow b/.github/main.workflow
index 7eea4c9..ce2a6f6 100644
--- a/.github/main.workflow
+++ b/.github/main.workflow
@@ -1,6 +1,9 @@
 workflow "Run tests" {
   on = "push"
-  resolves = ["mix test"]
+  resolves = [
+    "mix test",
+    "mix format",
+  ]
 }
 
 action "mix deps.get" {
@@ -13,3 +16,8 @@ action "mix test" {
   needs = ["mix deps.get"]
   args = "test --trace"
 }
+
+action "mix format" {
+  uses = "jclem/actions/mix@master"
+  args = "format --check-formatted"
+}