--- a/install/unix/preinstall
+++ b/install/unix/preinstall
@@ -121,7 +121,10 @@
 urels=`(uname -r) 2>/dev/null`
 machine=`(uname -m) 2>/dev/null`
 
-if [ "$uname" = "Darwin" ]; then
+if [ -d "Gentoo" -a -f "/etc/gentoo-release" ];  then
+    system="Gentoo"
+
+elif [ "$uname" = "Darwin" ]; then
     system="Darwin"
 
 elif [ "$machine" = "x86_64" ]; then