diff --git a/code_style.md b/code_style.md
index 676ee1a..3fb7125 100644
--- a/code_style.md
+++ b/code_style.md
@@ -60,6 +60,9 @@ Include the copyright notice as present in the template below the hash bang.
 
 Indent by four spaces.
 
+Don't have comments that go beyond 80 characters per line, preferably
+slightly less.
+
 Put special commands like `then` and `do` on the same line as the control
 structure they belong to. Use the same indent for special commands like
 `fi` and `done` as for the control structure they belong to.