diff --git a/.github/workflows/check.yml b/.github/workflows/check.yml
new file mode 100644
index 0000000..0445e6d
--- /dev/null
+++ b/.github/workflows/check.yml
@@ -0,0 +1,47 @@
+name: Check source
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+permissions:
+  contents: read
+
+jobs:
+  format:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v3
+      - name: Set up Python 3.9
+        uses: actions/setup-python@v3
+        with:
+          python-version: "3.9"
+      - name: Install dependencies
+        run: |
+          python -m pip install --upgrade pip
+          pip install poetry
+          poetry install
+      - name: Check format with black
+        run: |
+          poetry run black --check .
+
+  typing:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v3
+      - name: Set up Python 3.9
+        uses: actions/setup-python@v3
+        with:
+          python-version: "3.9"
+      - name: Install dependencies
+        run: |
+          python -m pip install --upgrade pip
+          pip install poetry
+          poetry install
+      - name: Check typing with mypy
+        run: |
+          poetry run mypy inlinehashes/
diff --git a/.github/workflows/pytest.yml b/.github/workflows/test.yml
similarity index 92%
rename from .github/workflows/pytest.yml
rename to .github/workflows/test.yml
index 1baedb7..6afe46f 100644
--- a/.github/workflows/pytest.yml
+++ b/.github/workflows/test.yml
@@ -13,7 +13,7 @@ permissions:
   contents: read
 
 jobs:
-  build:
+  test:
     runs-on: ubuntu-latest
 
     steps:
@@ -26,7 +26,7 @@ jobs:
         run: |
           python -m pip install --upgrade pip
           pip install poetry
-          poetry install --dev
+          poetry install
       - name: Test with pytest
         run: |
-          pytest
+          poetry run pytest
diff --git a/inlinehashes/lib.py b/inlinehashes/lib.py
index 361e812..66cbd2c 100644
--- a/inlinehashes/lib.py
+++ b/inlinehashes/lib.py
@@ -11,7 +11,7 @@ from itertools import chain
 import hashlib
 import base64
 
-from bs4 import BeautifulSoup, Tag
+from bs4 import BeautifulSoup, Tag  # type: ignore
 
 
 @dataclass(frozen=True)
@@ -199,7 +199,7 @@ def parse(content: str, target: str = "all") -> List[Inline]:
     if target == "all":
         search_queries = chain(*_VALID_TARGETS.values())
     elif target in _VALID_TARGETS.keys():
-        search_queries = _VALID_TARGETS[target]
+        search_queries = chain(_VALID_TARGETS[target])
     else:
         raise ValueError("Invalid Target")