diff --git a/en_US.ISO8859-1/slides/README b/en_US.ISO8859-1/slides/README
index a8e198b2c0..41b016f344 100644
--- a/en_US.ISO8859-1/slides/README
+++ b/en_US.ISO8859-1/slides/README
@@ -22,6 +22,9 @@ YYYYMMDD-eventname-title
 
 as required.
 
+Building the slides requires the Slides stylesheets to be installed -
+these are available from the textproc/slides port.
+
 From within a presentation directory, simply type 'make' to build an
 HTML version of the presentation.