--- a/src/HOL/Tools/Sledgehammer/MaSh/etc/settings	Fri Oct 04 18:27:07 2013 +0200
+++ b/src/HOL/Tools/Sledgehammer/MaSh/etc/settings	Sat Oct 05 11:06:07 2013 +0200
@@ -3,4 +3,6 @@
 ISABELLE_SLEDGEHAMMER_MASH="$COMPONENT"
 
 # MASH=yes
-MASH_PORT=9255
+if [ -z "$MASH_PORT" ]; then
+  MASH_PORT=9255
+fi