diff --git a/README.md b/README.md
index 1db48783..6d6094ab 100644
--- a/README.md
+++ b/README.md
@@ -79,19 +79,6 @@ unzip, and from within the directory run
     bundle exec jekyll serve
 
 
-## GNU sed and macOS
-
-The version of sed that ships with macOS is not fully compatible with the GNU sed.
-Therefore, you may get errors such as:
-```
-sed: 1: "out/plfa/Bisimulation.md": invalid command code o
-```
-You can fix this error by installing a GNU compatible version of sed, e.g. using [Homebrew](https://brew.sh/):
-```
-brew install gnu-sed --with-default-names
-```
-
-
 ## Unicode characters
 
 If you're having trouble typing the Unicode characters into Emacs, the end of