diff --git a/requirements-style.in b/requirements-style.in
index f9084250..b19b7d37 100644
--- a/requirements-style.in
+++ b/requirements-style.in
@@ -1,3 +1,4 @@
 flake8
 flake8-isort
 flake8-print
+pep8-naming
diff --git a/requirements-style.txt b/requirements-style.txt
index 647fbace..743bba12 100644
--- a/requirements-style.txt
+++ b/requirements-style.txt
@@ -4,10 +4,11 @@
 #
 flake8==3.5.0
 flake8-isort==2.3
-flake8-polyfill==1.0.2    # via flake8-isort
+flake8-polyfill==1.0.2    # via flake8-isort, pep8-naming
 flake8-print==3.0.1
 isort==4.2.15             # via flake8-isort
 mccabe==0.6.1             # via flake8
+pep8-naming==0.5.0
 pycodestyle==2.3.1        # via flake8, flake8-print
 pyflakes==1.6.0           # via flake8
 six==1.11.0               # via flake8-print