diff --git a/makefile b/makefile
index 65819c4..d27664b 100644
--- a/makefile
+++ b/makefile
@@ -5,7 +5,6 @@
 # https://stackoverflow.com/questions/448910
 # https://shiroyasha.svbtle.com/escape-sequences-a-quick-guide-1
 
-MAKEFLAGS += --warn-undefined-variables
 SHELL := /bin/bash
 .SHELLFLAGS := -O extglob -eo pipefail -c
 .DEFAULT_GOAL := help
diff --git a/setup.cfg b/setup.cfg
index bc3f4ba..0bc6fc3 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -21,10 +21,12 @@ ignore =
     E201
     # No whitespace before paren ")"
     E202
-    # No whitespace before ":"
+    # Whitespace before ":"
     E203
     # Multiple spaces before operator
     E221
+    # Multiple spaces after operand
+    E222
     # Multiple spaces before keyword
     E272
     # Spaces around keyword/parameter equals
@@ -41,6 +43,8 @@ ignore =
     # D101
     # Missing docstring on __init__
     D107
+    # First line should be in imperative mood
+    D401
 select = A,AAA,D,C,E,F,W,H,B,D212,D404,D405,D406,B901,B950
 exclude =
     .git