diff --git a/.github/workflows/CheckMainFile.yml b/.github/workflows/CheckMainFile.yml
new file mode 100644
index 0000000..539eaa1
--- /dev/null
+++ b/.github/workflows/CheckMainFile.yml
@@ -0,0 +1,11 @@
+name: Check build of CookieMonster
+on: [push, pull_request]
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+    - name: Check if CookieMonster.js is built correctly 
+      run: |
+        cat ./src/Header.js ./src/Cache.js ./src/Config.js ./src/Data.js ./src/Disp.js ./src/Main.js ./src/Sim.js ./src/Footer.js > CookieMonsterTest.js
+        cmp --silent CookieMonster.js CookieMonsterTest.js && echo '### SUCCESS: CookieMonster is correctly built! ###' || echo '### WARNING: CookieMonster.js does not seem to be correct. Have you compiled the source files into the final file using either of the combine files? ###'