diff --git a/HACKING.md b/HACKING.md
index dc5ef2bcc8d6a96d3ee5814acbb85452d5751f43..52f229c25efd9b54f64515dde29d297865c31c07 100644
--- a/HACKING.md
+++ b/HACKING.md
@@ -98,7 +98,7 @@ To build and test the `Cabal` library, do:
 
     We will refer to this as `PACKAGEDB`.
 
-5. Configure and build Cabal, and run all tests:
+5. Configure and build Cabal, and run all tests.  (Note that many of the package tests require shared libraries, which are not provided by GHC >= 7.8 on Windows: https://ghc.haskell.org/trac/ghc/ticket/8228)
 
     ~~~~
     ./Setup configure --enable-tests --package-db=$PACKAGEDB