Index: WPrefs.app/Makefile.in
--- WPrefs.app/Makefile.in.orig
+++ WPrefs.app/Makefile.in
@@ -481,6 +481,7 @@ WPrefs_SOURCES = \
 #	Themes.c
 AM_CFLAGS = 
 AM_CPPFLAGS = -DRESOURCE_PATH=\"$(wpdatadir)\" -DWMAKER_RESOURCE_PATH=\"$(pkgdatadir)\" \
+	 -DPREFIX=\"$(prefix)\" \
 	 -I$(top_srcdir)/wrlib -I$(top_srcdir)/WINGs @HEADER_SEARCH_PATH@ 
 
 WPrefs_DEPENDENCIES = $(top_builddir)/WINGs/libWINGs.la