diff -Nur xfwm4-4.6.1.orig/src/Makefile.in xfwm4-4.6.1/src/Makefile.in
--- xfwm4-4.6.1.orig/src/Makefile.in	2009-04-15 01:59:55.000000000 -0600
+++ xfwm4-4.6.1/src/Makefile.in	2010-02-13 14:29:19.000000000 -0700
@@ -107,7 +107,7 @@
 CCDEPMODE = @CCDEPMODE@
 CFLAGS = @CFLAGS@
 COMPOSITOR_CFLAGS = @COMPOSITOR_CFLAGS@
-COMPOSITOR_LIBS = @COMPOSITOR_LIBS@
+COMPOSITOR_LIBS = @COMPOSITOR_LIBS@ -lm
 CPP = @CPP@
 CPPFLAGS = @CPPFLAGS@
 CYGPATH_W = @CYGPATH_W@