diff --git a/.circleci/config.yml b/.circleci/config.yml
index 4f806b00f..fd7708f8d 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -84,11 +84,25 @@ jobs:
           command: make citest
       - store_test_results:
           path: test_libs/pyspec/test-reports
+  lint:
+    docker:
+      - image: circleci/python:3.6
+    working_directory: ~/specs-repo
+    steps:
+      - restore_cache:
+          key: v1-specs-repo-{{ .Branch }}-{{ .Revision }}
+      - restore_cached_venv:
+          venv_name: v1-pyspec
+          reqs_checksum: '{{ checksum "test_libs/pyspec/requirements.txt" }}-{{ checksum "test_libs/pyspec/requirements-testing.txt" }}'
+      - run:
+          name: Run linter
+          command: make install_lint && make pyspec && make lint
 workflows:
   version: 2.1
   test_spec:
     jobs:
       - checkout_specs
+      - lint
       - install_test:
           requires:
             - checkout_specs
diff --git a/Makefile b/Makefile
index 73d8adea8..8cc889f21 100644
--- a/Makefile
+++ b/Makefile
@@ -39,6 +39,13 @@ test: $(PY_SPEC_ALL_TARGETS)
 citest: $(PY_SPEC_ALL_TARGETS)
 	cd $(PY_SPEC_DIR); mkdir -p test-reports/eth2spec; . venv/bin/activate; python -m pytest --junitxml=test-reports/eth2spec/test_results.xml .
 
+install_lint:
+	cd $(PY_SPEC_DIR); python3 -m venv venv; . venv/bin/activate; pip3 install flake8==3.5.0
+
+lint:
+	cd $(PY_SPEC_DIR); . venv/bin/activate; \
+	flake8 --max-line-length=120 ./eth2spec;
+
 # "make pyspec" to create the pyspec for all phases.
 pyspec: $(PY_SPEC_ALL_TARGETS)