diff --git a/source/editor.rst b/source/editor.rst
index 8091041..fec3da2 100644
--- a/source/editor.rst
+++ b/source/editor.rst
@@ -52,6 +52,13 @@ Once installed, the command–line ``subl`` launcher will allow you to easily op
 Rulers
 //////
 
+According to `PEP8 <http://pep8.org/#maximum-line-length>`_, all lines of Python should typically be set to a maximum length of 79 charecters (72 if documentation). Let's configure Sublime Text to display these rulers. Go into *Preferences ➞ Settings*, and add the following JSON::
+
+    "rulers": [
+    	72,
+    	79,
+],
+
 
 
 Microsoft VS Code