http://bugzilla.xfce.org/show_bug.cgi?id=6629
http://bugs.gentoo.org/show_bug.cgi?id=331371

--- libxfce4panel/libxfce4panel-1.0.pc.in
+++ libxfce4panel/libxfce4panel-1.0.pc.in
@@ -2,6 +2,7 @@
 exec_prefix=@exec_prefix@
 libdir=@libdir@
 includedir=@includedir@
+localedir=@localedir@
 
 Name: libxfce4panel
 Description: Library for the Xfce Panel