diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index d6d8584..c065657 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -64,6 +64,13 @@ jobs:
         with:
           crate: cargo-sort
           version: "^1.0"
+      - name: check proto build up-to-date
+        run: |
+          cargo build --features prost-build
+          git diff --exit-code src/api.rs && echo "Up-to-date" || {
+              echo "Not up-to-date"
+              exit 1
+          }
       - name: check documentation
         env:
           RUSTDOCFLAGS: -D warnings