diff --git a/README b/README
index 86fe988..cebad30 100644
--- a/README
+++ b/README
@@ -35,6 +35,9 @@ Requirements
 Currently slstatus works on FreeBSD, Linux and OpenBSD.
 In order to build slstatus you need the Xlib header files.
 
+For volume percentage on Linux the kernel module `snd-mixer-oss` must be
+loaded.
+
 
 Installation
 ------------