diff --git a/Makefile.python b/Makefile.python
index f9ccfe8..c125562 100644
--- a/Makefile.python
+++ b/Makefile.python
@@ -1,61 +1,65 @@
 #    -*- mode: Makefile -*-
 
 PYMODULE := $(shell basename `pwd` | sed 's/-/./g')
 PYDIR := $(shell basename `pwd` | sed 's%-%/%g')
 
 PYTHON_BIN := $(shell test -d bin/ && find bin/ -type f -executable | xargs egrep -H '^\#.*python' | cut -f 1 -d :)
 TEST_DIRS := .
 
 TEST = python3 -m pytest
 TESTFLAGS =
 CODESPELL = codespell
 CODESPELLFLAGS =
+BLACK = python3 -m black
+BLACKFLAGS =
 FLAKE = python3 -m flake8
 FLAKEFLAGS =
 LINT = pylint3
 LINTFLAGS = --rcfile=../pylintrc
 MYPY = mypy
 MYPYFLAGS =
 
 all:
 
 .PHONY: test
 test:
 	$(TEST) $(TESTFLAGS) $(TEST_DIRS)
 
 .PHONY: coverage
 coverage:
 	$(TEST) $(TESTFLAGS) --cov=$(PYMODULE) --cov-branch $(TEST_DIRS)
 
-.PHONY: check check-flake check-codespell
-check: check-flake check-codespell check-mypy
+.PHONY: check check-black check-flake check-codespell check-mypy
+check: check-black check-flake check-codespell check-mypy
+check-black:
+	$(BLACK) $(BLACKFLAGS) --check swh $(PYTHON_BIN)
 check-flake:
 	$(FLAKE) $(FLAKEFLAGS) swh $(PYTHON_BIN)
 check-codespell:
 	find swh docs -name '*.py' -o -name '*.rst' | xargs -r $(CODESPELL) $(CODESPELLFLAGS)
 	find . -maxdepth 1 -iname 'readme*' | xargs -r $(CODESPELL) $(CODESPELLFLAGS)
 typecheck: check-mypy
 check-mypy:
 	$(MYPY) $(MYPYFLAGS) swh
 
 .PHONY: check-staged
 check-staged:
 	git diff -z --staged --name-only -- '*.py' $(PYTHON_BIN) \
 		| xargs -0 -L1 -i'{}' /bin/sh -c \
 		"git show ':{}' | $(FLAKE) $(FLAKEFLAGS) --stdin-display-name '{}' -"
 
 .PHONY: lint
 lint:
 	$(LINT) $(LINTFLAGS) $(PYMODULE)
 
 .PHONY: docs
 docs:
 	make -C docs
 
 .PHONY: distclean
 
 # Clean up Python bytecode files and a bunch of Python tool caches.
 distclean:
 	find . -type d -name __pycache__ | xargs rm -rf
 	find . -type f -name '*.pyc' -delete
 	rm -rf .tox/ .mypy_cache/