--- WindowMaker/Defaults/Makefile.in.orig	2013-01-10 06:43:07.000000000 +0900
+++ WindowMaker/Defaults/Makefile.in	2013-05-03 03:47:45.000000000 +0900
@@ -458,7 +458,9 @@
 
 WindowMaker: $(srcdir)/WindowMaker.in
 	-rm -f WindowMaker
-	sed -e "s:#pkgdatadir#:$(pkgdatadir):" $(srcdir)/WindowMaker.in \
+	sed -e "s:#pkgdatadir#:$(pkgdatadir):" \
+	    -e "s:#prefix#:$(prefix):" \
+		$(srcdir)/WindowMaker.in \
 		> WindowMaker
 	chmod 644 WindowMaker