--- a/tools/lint/flake8.yml
+++ b/tools/lint/flake8.yml
@@ -23,16 +23,17 @@ flake8:
         - testing/mozbase
         - testing/mochitest
         - testing/remotecppunittests.py
         - testing/runcppunittests.py
         - testing/talos/
         - testing/xpcshell
         - tools/git
         - tools/lint
+        - tools/mach_commands.py
         - tools/mercurial
         - tools/tryselect
         - toolkit/components/telemetry
     # Excludes should be added to topsrcdir/.flake8 due to a bug in flake8 where
     # specifying --exclude causes custom configuration files to be ignored.
     exclude: []
     # The configure option is used by the build system
     extensions: ['configure', 'py']

--- a/tools/mach_commands.py
+++ b/tools/mach_commands.py
@@ -213,19 +213,19 @@ class FormatProvider(MachCommandBase):
 
     def locate_or_fetch(self, root, python_script=False):
         # Download the clang-format binary & python clang-format-diff if doesn't
         # exists
         import urllib2
         import hashlib
         bin_sha = {
             "Windows": "5b6a236425abde1a04ff09e74d8fd0fee1d49e5a35e228b24d77366cab03e1141b8073eec1b36c43e265a80bee707baaa7f96856b4820cbb02069775e58a3f9d",  # noqa: E501
-            "Linux": "64444efd9b6895447359a9f70d6781251e74d7881f993b5d81a19f8e6a8503f798d42506061fb9eb48729b7327c42a9d273c80dde18816a350fdbc020ebfa783", # noqa: E501
+            "Linux": "64444efd9b6895447359a9f70d6781251e74d7881f993b5d81a19f8e6a8503f798d42506061fb9eb48729b7327c42a9d273c80dde18816a350fdbc020ebfa783",  # noqa: E501
             "Darwin": "d9b08e21c233426628e39dd49bbb9b4e43cccb9aeb78d043dec2bdf6b1eacafddd13488558d38dfa0a0d39946b03b72c58933f1f79d638c045353cf3f4ae0fa4",  # noqa: E501
-            "python_script": "051b8c8932085616a775ef8b7b1384687db8f37660938f94e9389bf6dba6f6e244d2dc63d23e1d2bf8ab96c9bd5244faefc5218a1f90d5ec692698f0094a3238", # noqa: E501
+            "python_script": "051b8c8932085616a775ef8b7b1384687db8f37660938f94e9389bf6dba6f6e244d2dc63d23e1d2bf8ab96c9bd5244faefc5218a1f90d5ec692698f0094a3238",  # noqa: E501
         }
 
         target = os.path.join(self._mach_context.state_dir, os.path.basename(root))
 
         if not os.path.exists(target):
             tooltool_url = "https://tooltool.mozilla-releng.net/sha512/"
             if self.prompt and raw_input("Download clang-format executables from {0} (yN)? ".format(tooltool_url)).lower() != 'y':  # noqa: E501,F821
                 print("Download aborted.")
@@ -318,17 +318,18 @@ class FormatProvider(MachCommandBase):
                 continue
 
             if os.path.isdir(f):
                 # Processing a directory, generate the file list
                 for folder, subs, files in os.walk(f):
                     subs.sort()
                     for filename in sorted(files):
                         f_in_dir = os.path.join(folder, filename)
-                        if f_in_dir.endswith(extensions) and not re.match(ignored_dir_re, f_in_dir):
+                        if (f_in_dir.endswith(extensions)
+                            and not re.match(ignored_dir_re, f_in_dir)):
                             # Supported extension and accepted path
                             path_list.append(f_in_dir)
             else:
                 if f.endswith(extensions):
                     path_list.append(f)
 
         return path_list