diff -r 8eb8640d7300 -r f3039309702e src/Pure/Tools/debugger.ML
--- a/src/Pure/Tools/debugger.ML	Mon Aug 10 21:06:10 2015 +0200
+++ b/src/Pure/Tools/debugger.ML	Mon Aug 10 21:11:15 2015 +0200
@@ -213,8 +213,7 @@
   ML_Debugger.on_breakpoint
     (SOME (fn (_, break) =>
       if not (is_debugging ()) andalso
-        (! break orelse Options.default_bool @{system_option ML_debugger_stepping} orelse
-          is_stepping ()) andalso
+        (! break orelse is_stepping ()) andalso
         Options.default_bool @{system_option ML_debugger_active}
       then
         (case Simple_Thread.get_name () of