Index: WINGs/Makefile.in
--- WINGs/Makefile.in.orig
+++ WINGs/Makefile.in
@@ -553,6 +553,7 @@ libWUtil_la_SOURCES = \
 
 AM_CFLAGS = 
 AM_CPPFLAGS = -DRESOURCE_PATH=\"$(datadir)/WINGs\" \
+	 -DPREFIX=\"$(prefix)\" \
 	 -I$(top_srcdir)/WINGs/WINGs -I$(top_srcdir)/wrlib -I$(top_srcdir)/src \
 	@XFTFLAGS@ @HEADER_SEARCH_PATH@