diff --git a/.github/workflows/no-submodule-update.yml b/.github/workflows/no-submodule-update.yml
new file mode 100644
index 0000000000..f2a9d72e37
--- /dev/null
+++ b/.github/workflows/no-submodule-update.yml
@@ -0,0 +1,14 @@
+name: No submodule update checker
+
+on:
+  pull_request:
+    paths:
+      - 'RobustToolbox'
+
+jobs:
+  this_aint_right:
+    name: Submodule update in pr found
+    runs-on: ubuntu-latest
+    steps:
+      - name: Fail
+        run: exit 1