diff --git a/.github/workflows/validation.yml b/.github/workflows/validation.yml
index 6d09287..94291b8 100644
--- a/.github/workflows/validation.yml
+++ b/.github/workflows/validation.yml
@@ -33,7 +33,7 @@ jobs:
           restore-keys: "precommit-${{ runner.os }}-${{ steps.poetry_setup.outputs-python-version}}-"
 
       - name: Run pre-commit hooks
-        run: SKIP=ruff-linter,ruff-formatter,basedpyright pre-commit run --all-files
+        run: SKIP=ruff-linter,ruff-formatter,slotscheck,basedpyright pre-commit run --all-files
 
       - name: Run ruff linter
         run: ruff check --output-format=github --show-fixes --exit-non-zero-on-fix .
@@ -41,5 +41,8 @@ jobs:
       - name: Run ruff formatter
         run: ruff format --diff .
 
+      - name: Run slotscheck
+        run: slotscheck -m mcproto
+
       - name: Run basedpyright type checker
         run: basedpyright --warnings .
diff --git a/pyproject.toml b/pyproject.toml
index cbdeb7a..f199598 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -170,7 +170,7 @@ addopts = "--strict-markers --cov --no-cov-on-fail"
 
 [tool.coverage.report]
 precision = 2
-fail_under = 0
+fail_under = 20
 show_missing = true
 skip_covered = false
 skip_empty = false