diff --git a/.github/workflows/format.yml b/.github/workflows/format.yml
index 89b8239..3353df6 100644
--- a/.github/workflows/format.yml
+++ b/.github/workflows/format.yml
@@ -1,4 +1,4 @@
-name: Prettier
+name: Lint and format
 
 on: push
 
@@ -27,7 +27,7 @@ jobs:
           flake8 . --count --exit-zero --max-complexity=10 --max-line-length=127 --statistics
 
       - name: Format with black
-        run: black --check .
+        run: black .
 
       - name: Commit changes
         uses: stefanzweifel/git-auto-commit-action@v4.1.2
diff --git a/app/fb2.py b/app/fb2.py
index 1771147..8cd4129 100644
--- a/app/fb2.py
+++ b/app/fb2.py
@@ -1,7 +1,7 @@
 from tempfile import SpooledTemporaryFile
 import xml.etree.ElementTree as ET
 from xml.etree.ElementTree import Element
-from typing import Optional, Union
+from typing import Optional
 from fastapi import HTTPException
 
 from .utils import Document_Tokens, strip_whitespace
@@ -71,7 +71,7 @@ def fb22tokens(file: SpooledTemporaryFile) -> Document_Tokens:
         metadata["title"] = book_info.find("./book-title", namespaces).text
         metadata["author"] = get_author(book_info.find("./author", namespaces))
         metadata["cover"] = get_cover(book_info.find("./coverpage", namespaces))
-        if not "cover" in metadata.keys():
+        if "cover" not in metadata.keys():
             metadata.pop("cover")
 
         if len(metadata.keys()):
@@ -108,7 +108,7 @@ def get_author(author: Element) -> str:
         "last-name",
     ):
         el = author.find("./" + tag_name, namespaces)
-        if not el is None:
+        if el is not None:
             res.append(el.text)
     if len(res) == 0:
         res = author.find("./nickname", namespaces).text
diff --git a/app/main.py b/app/main.py
index fb5382e..3810ce0 100644
--- a/app/main.py
+++ b/app/main.py
@@ -1,6 +1,4 @@
 from fastapi import FastAPI, File, UploadFile, HTTPException
-from fastapi.responses import HTMLResponse
-from typing import Union
 
 from .epub import epub2html
 from .fb2 import fb22html
diff --git a/requirements.txt b/requirements.txt
index 17e1775..97ea19d 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,13 +1,23 @@
 aiofiles==0.7.0
+appdirs==1.4.4
 asgiref==3.4.0
+black==21.6b0
 click==8.0.1
 EbookLib==0.17.1
 fastapi==0.65.2
+flake8==3.9.2
 h11==0.12.0
 lxml==4.6.3
+mccabe==0.6.1
+mypy-extensions==0.4.3
+pathspec==0.8.1
+pycodestyle==2.7.0
 pydantic==1.8.2
+pyflakes==2.3.1
 python-multipart==0.0.5
+regex==2021.7.1
 six==1.16.0
 starlette==0.14.2
+toml==0.10.2
 typing-extensions==3.10.0.0
 uvicorn==0.14.0