diff --git a/_pytest/python_api.py b/_pytest/python_api.py
index b73e0457c..a3cf1c8cb 100644
--- a/_pytest/python_api.py
+++ b/_pytest/python_api.py
@@ -217,7 +217,8 @@ class ApproxScalar(ApproxBase):
         absolute tolerance or a relative tolerance, depending on what the user
         specified or which would be larger.
         """
-        def set_default(x, default): return x if x is not None else default
+        def set_default(x, default):
+            return x if x is not None else default
 
         # Figure out what the absolute tolerance should be.  ``self.abs`` is
         # either None or a value specified by the user.
diff --git a/tox.ini b/tox.ini
index 9245ff418..33e5fa02c 100644
--- a/tox.ini
+++ b/tox.ini
@@ -213,3 +213,8 @@ filterwarnings =
 [flake8]
 max-line-length = 120
 exclude = _pytest/vendored_packages/pluggy.py
+ignore=
+    # do not use bare except'
+    E722
+    # ambiguous variable name 'l'
+    E741