diff -urN libxml2-2.7.2/configure.in libxml2-2.7.2-haiku/configure.in
--- libxml2-2.7.2/configure.in	2008-10-03 07:09:55.000000000 +0000
+++ libxml2-2.7.2-haiku/configure.in	2008-10-22 19:07:34.000000000 +0000
@@ -1257,6 +1257,8 @@
 	;;
 	*beos*) M_LIBS=""
 	;;
+	*haiku*) M_LIBS=""
+	;;
 	*) M_LIBS="-lm"
 	;;
 esac