diff --git a/build b/build
index 31d9de3..d725669 100755
--- a/build
+++ b/build
@@ -21,7 +21,7 @@ coverage run \
   -m unittest discover
 
 # Check that source has correct formatting.
-yapf --diff --recursive --style google ./ --exclude=./third_party/*
+yapf --diff --recursive --style google ./ --exclude=third_party/*
 
 # Run static analysis for Python bugs/cruft.
 pyflakes "${SOURCE_DIR}/" "${TEST_DIR}/"
diff --git a/dev_requirements.txt b/dev_requirements.txt
index 9edefa8..102001c 100644
--- a/dev_requirements.txt
+++ b/dev_requirements.txt
@@ -1,8 +1,8 @@
 # pylint versions prior to 1.5.0 require this specific version of astroid.
 astroid==1.3.8
 mock
-pyflakes==1.6.0
+pyflakes==2.0.0
 # We use pylint exclusively to run the DocStringChecker linter and that linter
 # expects pre-1.5.0 pylint syntax.
 pylint==1.4.4
-yapf==0.20.1
+yapf==0.22.0