diff --git a/.flake8 b/.flake8
index 6c33bfe70..2413bf098 100644
--- a/.flake8
+++ b/.flake8
@@ -12,14 +12,11 @@
 # Nice-to-haves ignored for now
 #   152 E128 continuation line under-indented for visual indent
 #    43 E127 continuation line over-indented for visual indent
+#     6 E999 invalid syntax - FIXME: re-enable after flake8 is running from Python 3.6
 
 [flake8]
-ignore = F401, F811, F821, E127, E128, E301, E302, E305, E501, E701, E704, E999, B303
+ignore = F401, F811, E127, E128, E301, E302, E305, E501, E701, E704, E999, B303
 # We are checking with Python 3 but many of the stubs are Python 2 stubs.
 # A nice future improvement would be to provide separate .flake8
 # configurations for Python 2 and Python 3 files.
 builtins = StandardError,apply,basestring,buffer,cmp,coerce,execfile,file,intern,long,raw_input,reduce,reload,unichr,unicode,xrange
-
-# Errors that we need to fix before enabling flake8 by default:
-#    92 F821 undefined name - FIXME: re-enable and add missing imports
-#     6 E999 invalid syntax - FIXME: re-enable after flake8 is running from Python 3.6
diff --git a/.travis.yml b/.travis.yml
index 9e6a51463..239c3870a 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -12,7 +12,7 @@ matrix:
 
 install:
   # pytype needs py-2.7, mypy needs py-3.2+. Additional logic in runtests.py
-  - if [[ $TRAVIS_PYTHON_VERSION == '3.5' ]]; then pip install -U git+git://github.com/python/mypy git+git://github.com/dropbox/typed_ast flake8==3.2.1 flake8-bugbear flake8-pyi; fi
+  - if [[ $TRAVIS_PYTHON_VERSION == '3.5' ]]; then pip install -U git+git://github.com/python/mypy git+git://github.com/dropbox/typed_ast flake8==3.2.1 flake8-bugbear>=16.12.2 flake8-pyi>=16.12.1; fi
   - if [[ $TRAVIS_PYTHON_VERSION == '2.7' ]]; then pip install -U git+git://github.com/google/pytype; fi
 
 script:
diff --git a/requirements-tests-py3.txt b/requirements-tests-py3.txt
index 66d4a2077..e6ffb9113 100644
--- a/requirements-tests-py3.txt
+++ b/requirements-tests-py3.txt
@@ -2,4 +2,4 @@ mypy-lang>=0.4.6
 typed-ast>=0.6.1
 flake8==3.2.1
 flake8-bugbear>=16.12.2
-flake8-pyi>=16.12.0
+flake8-pyi>=16.12.1