special-case Darwin (bug 4509)
diff --git a/bin/installmesa b/bin/installmesa
index 0bfce33..49a385f 100755
--- a/bin/installmesa
+++ b/bin/installmesa
@@ -51,6 +51,8 @@
 
 if [ `uname` = "FreeBSD" ] ; then
 	CP_FLAGS="-f"
+elif [ `uname` = "Darwin" ] ; then
+	CP_FLAGS="-f"
 else
 	CP_FLAGS="-fd"
 fi