diff --git a/README.md b/README.md
index f642cac..669e442 100644
--- a/README.md
+++ b/README.md
@@ -10,23 +10,15 @@ This linter plugin for [SublimeLinter](https://github.com/SublimeLinter/SublimeL
 
 SublimeLinter must be installed in order to use this plugin. 
 
-Please install via [Package Control](https://packagecontrol.io).
+Install via [Package Control](https://packagecontrol.io) or `git clone` as usual.
 
-Before installing this plugin, ensure that `flake8` is installed on your system.
-To install `flake8`, do the following:
+Ensure that a `flake8` is actually installed somewhere on your system. Typically, `pip install flake8` on the command line will do that.
 
-1. Install [Python](http://python.org) and [pip](http://www.pip-installer.org/en/latest/installing.html) (Python 3 requires pip3).
+If you want to use a globally installed flake, make sure that it is available on the PATH. Before going any further, please read and follow the steps in ["Finding a linter executable"](http://sublimelinter.com/en/latest/troubleshooting.html#finding-a-linter-executable) through "Validating your PATH" in the documentation.
 
-1. Install `flake8` (2.1 or later) by typing the following in a terminal:
-   ```
-   # For python2
-   [sudo] pip install flake8
+Otherwise configure ["executable"](http://www.sublimelinter.com/en/latest/linter_settings.html#executable) or the ["python"](http://www.sublimelinter.com/en/latest/linter_settings.html#python) setting. 
 
-   # For python 3
-   [sudo] pip3 install flake8
-   ```
-
-Please make sure that the path to `flake8` is available to SublimeLinter. Before going any further, please read and follow the steps in ["Finding a linter executable"](http://sublimelinter.com/en/latest/troubleshooting.html#finding-a-linter-executable) through "Validating your PATH" in the documentation.
+If you use pipenv, and you're working on a project with a Pipfile, everything should be automatic.
 
 
 ## Settings
@@ -34,4 +26,11 @@ Please make sure that the path to `flake8` is available to SublimeLinter. Before
 - SublimeLinter settings: http://sublimelinter.com/en/latest/settings.html
 - Linter settings: http://sublimelinter.com/en/latest/linter_settings.html
 
-SublimeLinter-flake8 works with common flake8 [configuration files](http://flake8.pycqa.org/en/latest/user/configuration.html#configuration-locations) and inline overrides.
+Additional setting:
+
+- 'ignore_fixables' (Default: True): Filter warnings that Sublime can fix automatically (e.g. trailing white-space) on save.
+
+SublimeLinter-flake8 works with common flake8 [configuration files](http://flake8.pycqa.org/en/latest/user/configuration.html#configuration-locations) and inline overrides. Note that, by default the [working dir](http://www.sublimelinter.com/en/latest/linter_settings.html#working-dir) is set to an open folder attached to the current window of Sublime. This is of importance if your config files are located in a subfolder for example. 
+
+Use ["args"](http://www.sublimelinter.com/en/latest/linter_settings.html#args) if you want to set some arguments just like on the command line.
+
diff --git a/linter.py b/linter.py
index 4937da3..00faffc 100644
--- a/linter.py
+++ b/linter.py
@@ -1,7 +1,11 @@
+import logging
 from SublimeLinter.lint import PythonLinter
 import re
 
 
+logger = logging.getLogger('SublimeLinter.plugins.flake8')
+
+
 CAPTURE_WS = re.compile(r'(\s+)')
 CAPTURE_IMPORT_ID = re.compile(r'^\'(?:.*\.)?(.+)\'')
 
@@ -10,7 +14,10 @@ class Flake8(PythonLinter):
 
     cmd = ('flake8', '--format', 'default', '${args}', '-')
     defaults = {
-        'selector': 'source.python'
+        'selector': 'source.python',
+
+        # Ignore codes Sublime can auto-fix
+        'ignore_fixables': True
     }
 
     # The following regex marks these pyflakes and pep8 codes as errors.
@@ -40,6 +47,58 @@ class Flake8(PythonLinter):
     )
     multiline = True
 
+    def on_stderr(self, stderr):
+        # For python 3.7 we actually have the case that flake yields
+        # FutureWarnings. We just eat those as they're irrelevant here. Note
+        # that we try to eat the subsequent line as well which usually contains
+        # the culprit source line.
+        stderr = re.sub(r'^.+FutureWarning.+\n(.*\n?)?', '', stderr, re.M)
+        stderr = re.sub(r'^.+DeprecationWarning.+\n(.*\n?)?', '', stderr, re.M)
+
+        if stderr:
+            self.notify_failure()
+            logger.error(stderr)
+
+    def parse_output(self, proc, virtual_view):
+        settings = self.get_view_settings()
+        errors = super().parse_output(proc, virtual_view)
+
+        if not settings.get('ignore_fixables', True):
+            return errors
+
+        trims_ws = self.view.settings().get('trim_trailing_white_space_on_save')
+        ensures_newline = self.view.settings().get('ensure_newline_at_eof_on_save')
+
+        if not (trims_ws or ensures_newline):
+            return errors
+
+        filtered_errors = []
+        for error in errors:
+            code = error['code']
+
+            if ensures_newline and code == 'W292':
+                continue
+
+            if trims_ws and code in ('W291', 'W293'):
+                continue
+
+            if trims_ws and code == 'W391':
+                # Fixable if one WS line is at EOF, except the view only has
+                # one line.
+                lines = len(virtual_view._newlines) - 1
+                if (
+                    virtual_view.select_line(lines - 1).strip() == ''
+                    and (
+                        lines < 2
+                        or virtual_view.select_line(lines - 2).strip() != ''
+                    )
+                ):
+                    continue
+
+            filtered_errors.append(error)
+
+        return filtered_errors
+
     def reposition_match(self, line, col, m, virtual_view):
         """Reposition white-space errors."""
         code = m.error or m.warning
diff --git a/messages.json b/messages.json
index ae59b07..4240581 100644
--- a/messages.json
+++ b/messages.json
@@ -1,4 +1,4 @@
 {
     "install": "messages/install.txt",
-    "4.0.0-rc.1": "messages/4.0.0-rc.1.txt"
+    "4.2.0": "messages/4.2.0.txt"
 }
diff --git a/messages/4.0.0-rc.1.txt b/messages/4.0.0-rc.1.txt
deleted file mode 100644
index c332fac..0000000
--- a/messages/4.0.0-rc.1.txt
+++ /dev/null
@@ -1,6 +0,0 @@
-SublimeLinter-flake8 4.0.0-rc.1
--------------------------------
-
-Thank you for using the beta release of SublimeLinter-flake8!
-If you run into anything please report at:
-https://github.com/SublimeLinter/SublimeLinter3/issues
diff --git a/messages/4.2.0.txt b/messages/4.2.0.txt
new file mode 100644
index 0000000..82bf146
--- /dev/null
+++ b/messages/4.2.0.txt
@@ -0,0 +1,24 @@
+SublimeLinter-flake8 4.2.0
+--------------------------
+
+Less noise, hide problems that can be fixed automatically!
+
+Sublime has a basic code formatter built in. E.g. it will remove trailing white-space on save. (The related Sublime settings here are "trim_trailing_white_space_on_save" and "ensure_newline_at_eof_on_save".) 
+
+Starting with this release, we will filter (hide) these errors automatically. We introduce a new setting "ignore_fixables" (True by default) which controls this behavior.
+
+Maybe you already know black, the new, zero-config code formatter for python. And in case you use it, you may have noticed that flake8 now produces a lot of noise which black can fix for you. There is an addon https://packagecontrol.io/packages/SublimeLinter-addon-black-for-flake which will automatically filter all warnings black can fix. Try it!
+
+
+Notable enhancement: Mark unused imported identifiers correct. E.g. in the following code, 
+
+    from x import (
+        x,
+        y,
+        z
+    )
+
+we now correctly highlight x, y, and z.
+
+Fix: Tighten compatibility with python 3.7
+