diff --git a/Makefile b/Makefile
index 85829f5..c580632 100644
--- a/Makefile
+++ b/Makefile
@@ -1,7 +1,7 @@
 # This file has been auto-generated.
 # All changes will be lost, see Projectfile.
 #
-# Updated at 2016-12-28 11:17:56.199090
+# Updated at 2016-12-28 15:50:31.026587
 
 PYTHON ?= $(shell which python)
 PYTHON_BASENAME ?= $(shell basename $(PYTHON))
@@ -16,8 +16,10 @@ SPHINX_OPTS ?=
 SPHINX_BUILD ?= $(VIRTUAL_ENV)/bin/sphinx-build
 SPHINX_SOURCEDIR ?= docs
 SPHINX_BUILDDIR ?= $(SPHINX_SOURCEDIR)/_build
+YAPF ?= $(VIRTUAL_ENV)/bin/yapf
+YAPF_OPTIONS ?= -rip
 
-.PHONY: $(SPHINX_SOURCEDIR) clean install install-dev lint test
+.PHONY: $(SPHINX_SOURCEDIR) clean format install install-dev lint test
 
 # Installs the local project dependencies.
 install: $(VIRTUAL_ENV)
@@ -50,3 +52,6 @@ test: install-dev
 
 $(SPHINX_SOURCEDIR): install-dev
 	$(SPHINX_BUILD) -b html -D latex_paper_size=a4 $(SPHINX_OPTS) $(SPHINX_SOURCEDIR) $(SPHINX_BUILDDIR)/html
+
+format: install-dev
+	$(YAPF) $(YAPF_OPTIONS) .
diff --git a/Projectfile b/Projectfile
index 7136ebf..b4ea177 100644
--- a/Projectfile
+++ b/Projectfile
@@ -17,6 +17,7 @@ enable_features = {
     'git',
     'pylint',
     'python',
+    'yapf',
 }
 
 install_requires = [
diff --git a/bonobo/core/contexts.py b/bonobo/core/contexts.py
index aa66a98..6a4d7f0 100644
--- a/bonobo/core/contexts.py
+++ b/bonobo/core/contexts.py
@@ -10,6 +10,7 @@ from bonobo.core.stats import WithStatistics
 from bonobo.util.lifecycle import get_initializer, get_finalizer
 from bonobo.util.tokens import BEGIN, END, NEW, RUNNING, TERMINATED, NOT_MODIFIED
 
+
 class ExecutionContext:
     def __init__(self, graph, plugins=None):
         self.graph = graph