diff --git a/demos/modules/gwin/widgets/readme.txt b/demos/modules/gwin/widgets/readme.txt
index 02d733e9..bb91e810 100644
--- a/demos/modules/gwin/widgets/readme.txt
+++ b/demos/modules/gwin/widgets/readme.txt
@@ -4,3 +4,7 @@ gfxconf.h
 
 Note that you will need to include the drivers into your project
 makefile for whichever inputs you decide to use.
+
+Note that you need to link to the math library. Add -lm to your 
+library paths in your Makefile.
+