diff --git a/.github/workflows/changes.yml b/.github/workflows/changes.yml
new file mode 100644
index 00000000..27f9f390
--- /dev/null
+++ b/.github/workflows/changes.yml
@@ -0,0 +1,20 @@
+name: Changes check
+
+on:
+  push:
+    paths:
+      - "src/lib/grammar/FilLexer.g4"
+      - "src/lib/grammar/FilParser.g4"
+      - ".github/workflows/changes.yml"
+
+jobs:
+  diagram:
+    name: Diagram check
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+
+      - name: Generate diagram
+        run: ${{github.workspace}}/bin/railroad_diagram.sh
+      - name: Check no changes
+        run: ${{github.workspace}}/bin/check_no_changes.sh
\ No newline at end of file
diff --git a/bin/check_no_changes.sh b/bin/check_no_changes.sh
new file mode 100755
index 00000000..cac9cb1e
--- /dev/null
+++ b/bin/check_no_changes.sh
@@ -0,0 +1,7 @@
+#!/bin/bash
+
+if [[ -z "$(git status --porcelain)" ]]; then
+  exit 0
+else
+  exit 1
+fi