diff --git a/.circleci/config.yml b/.circleci/config.yml
index a40cec1..639916f 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -6,6 +6,23 @@ jobs:
     steps:
       - checkout
       - run: go build ./...
+  format:
+    docker:
+      - image: golang:latest
+    steps:
+      - checkout
+      - run:
+          name: Install gofumports outside local module
+          command: |
+            cd $(mktemp -d) &&
+            go mod init tmp &&
+            go get mvdan.cc/gofumpt/gofumports@latest
+      - run:
+          name: Run gofumports on all non-generated files
+          command: grep -L -R "^\/\/ Code generated .* DO NOT EDIT\.$" --exclude-dir=.git --exclude-dir=vendor --include="*.go" | xargs -n 1 gofumports -w -local github.com/johanbrandhorst/certify
+      - run:
+          name: Check for any changes
+          command: git diff --exit-code
   vendor:
     docker:
       - image: golang:latest
@@ -59,6 +76,7 @@ workflows:
   all:
     jobs:
       - build
+      - format
       - vendor
       - generate
       - test