diff --git a/README.md b/README.md
index 7ef598c018a54f1850f1c8523568d10e6bfd51df..365312e7759745f3649be0847b2d3a9868461507 100644
--- a/README.md
+++ b/README.md
@@ -82,6 +82,7 @@ handles your haskell packages and can demand that [a specific version](https://c
 ### Manpages
 
 For man pages to work you need [man-db](http://man-db.nongnu.org/) as your `man` provider, then issue `man ghc`. Manpages only work for the currently set ghc.
+`MANPATH` may be required to be unset.
 
 ## Design goals