--- a/lib/App/Ack/ConfigDefault.pm
+++ b/lib/App/Ack/ConfigDefault.pm
@@ -280,6 +280,10 @@
 # https://en.wikipedia.org/wiki/Fortran
 --type-add=fortran:ext:f,f77,f90,f95,f03,for,ftn,fpp
 
+# Gentoo
+# https://www.gentoo.org/
+--type-add=gentoo:ext:ebuild,eclass
+
 # Go
 # https://golang.org/
 --type-add=go:ext:go