diff --git a/kvmstats.sh b/kvmstats.sh
index 140aa06..8967452 100644
--- a/kvmstats.sh
+++ b/kvmstats.sh
@@ -1,5 +1,9 @@
 #!/bin/sh
 
+# NOTE: kvmstats relies on the hxselect command to parse virsh' xml
+# files. On Debian, this command is provided by the 'html-xml-utils'
+# package.
+
 usage () {
     echo 'usage: kvmstats.sh [-u K|M|G]'
     exit 1