diff --git a/C/modules.c b/C/modules.c
index 5611ee11b..8a62419f6 100644
--- a/C/modules.c
+++ b/C/modules.c
@@ -55,6 +55,9 @@ LookupModule(Term a)
     if (ModuleName[i] == a)
       return (i);
   ModuleName[i = NoOfModules++] = a;
+  if (NoOfModules == MaxModules) {
+    Error(SYSTEM_ERROR,a,"number of modules overflowed");
+  }
   return (i);
 }
 
diff --git a/C/tracer.c b/C/tracer.c
index 1b899a345..93be90e8d 100644
--- a/C/tracer.c
+++ b/C/tracer.c
@@ -112,7 +112,7 @@ low_level_trace(yap_low_level_port port, PredEntry *pred, CELL *args)
   /*  extern int gc_calls; */
 
   vsc_count++;
-  /* if (vsc_count < 84600) return; */
+  /* if (vsc_count < 3887174000LL) return; */
   /*
   if (vsc_count == 4376) {
     printf("Here I go\n");
diff --git a/m4/Yatom.h.m4 b/m4/Yatom.h.m4
index 40b36d1a3..3c33fdec8 100644
--- a/m4/Yatom.h.m4
+++ b/m4/Yatom.h.m4
@@ -386,7 +386,7 @@ typedef enum {
   DBWithRefs = 0x40
 } db_term_flags;
 
-#define MaxModules	255
+#define MaxModules	256
 
 typedef	struct {
   Prop	NextOfPE;	     /* used to chain properties		*/
diff --git a/pl/boot.yap b/pl/boot.yap
index 1b276c907..92c3a1d01 100644
--- a/pl/boot.yap
+++ b/pl/boot.yap
@@ -983,9 +983,10 @@ break :- '$get_value'('$break',BL), NBL is BL+1,
 	'$change_alias_to_stream'('$loop_stream',Stream),
 	repeat,
 		( '$current_stream'(_,_,Stream) -> true
-		 ; '$current_module'(_,OldModule), '$abort_loop'(Stream)
+		 ; '$abort_loop'(Stream)
 		),
 		prompt('|     '), prompt(_,'| '),
+		'$current_module'(OldModule),
 		'$system_catch'('$enter_command'(Stream,Status), OldModule, Error,
 			 user:'$LoopError'(Error)),
 	!.