diff -r f4bb3068d819 -r 22b87ab47d3b src/Tools/quickcheck.ML
--- a/src/Tools/quickcheck.ML	Thu Oct 30 23:14:11 2014 +0100
+++ b/src/Tools/quickcheck.ML	Fri Oct 31 11:18:17 2014 +0100
@@ -90,16 +90,6 @@
 val unknownN = "unknown";
 
 
-(* preferences *)
-
-val _ =
-  ProofGeneral.preference_option ProofGeneral.category_tracing
-    NONE
-    @{system_option auto_quickcheck}
-    "auto-quickcheck"
-    "Run Quickcheck automatically";
-
-
 (* quickcheck report *)
 
 datatype report = Report of