--- rxvt-unicode/configure	2004/12/01 02:33:32	1.42
+++ rxvt-unicode/configure	2004/12/20 16:47:14	1.43
@@ -3284,7 +3284,7 @@
 LINKER=$LINKER
 
 
-CPPFLAGS="-D_GNU_SOURCE -D_XOPEN_SOURCE"
+CPPFLAGS="-D_GNU_SOURCE -D_XOPEN_SOURCE=2"
 
 
 ac_ext=cc