diff --git a/mps/src/arena.c b/mps/src/arena.c
index cddaf115aea..b33c13f8b20 100644
--- a/mps/src/arena.c
+++ b/mps/src/arena.c
@@ -1,6 +1,6 @@
 /* impl.c.arena: ARENA IMPLEMENTATION
  *
- * $HopeName: MMsrc!arena.c(trunk.35) $
+ * $HopeName: MMsrc!arena.c(trunk.36) $
  * Copyright (C) 1998. Harlequin Group plc. All rights reserved.
  *
  * .readership: Any MPS developer
@@ -36,7 +36,7 @@
 #include "poolmrg.h"
 #include "mps.h"
 
-SRCID(arena, "$HopeName: MMsrc!arena.c(trunk.35) $");
+SRCID(arena, "$HopeName: MMsrc!arena.c(trunk.36) $");
 
 
 /* All static data objects are declared here. See .static */
@@ -474,8 +474,6 @@ Bool ArenaAccess(Addr addr, AccessSet mode, MutatorFaultContext context)
   Seg seg;
   Ring node, nextNode;
 
-  UNUSED(context);
-
   LockClaim(&arenaRingLock);    /* design.mps.arena.lock.ring */
   RING_FOR(node, &arenaRing, nextNode) {
     Arena arena = RING_ELT(Arena, globalRing, node);
@@ -496,7 +494,7 @@ Bool ArenaAccess(Addr addr, AccessSet mode, MutatorFaultContext context)
        */
       mode &= SegPM(seg);
       if(mode != AccessSetEMPTY)
-        PoolAccess(SegPool(seg), seg, addr, mode);
+        PoolAccess(SegPool(seg), seg, addr, mode, context);
       ArenaLeave(arena);
       return TRUE;
     } else if(RootOfAddr(&root, arena, addr)) {
diff --git a/mps/src/mpm.h b/mps/src/mpm.h
index f0adb7d1c52..fd2e0f4acd0 100644
--- a/mps/src/mpm.h
+++ b/mps/src/mpm.h
@@ -1,6 +1,6 @@
 /* impl.h.mpm: MEMORY POOL MANAGER DEFINITIONS
  *
- * $HopeName: MMsrc!mpm.h(trunk.81) $
+ * $HopeName: MMsrc!mpm.h(trunk.82) $
  * Copyright (C) 1998. Harlequin Group plc. All rights reserved.
  */
 
@@ -278,7 +278,8 @@ extern void PoolDestroy(Pool pool);
 extern Res PoolAlloc(Addr *pReturn, Pool pool, Size size);
 extern void PoolFree(Pool pool, Addr old, Size size);
 extern Res PoolTraceBegin(Pool pool, Trace trace);
-extern Res PoolAccess(Pool pool, Seg seg, Addr addr, AccessSet mode);
+extern Res PoolAccess(Pool pool, Seg seg, Addr addr,
+                      AccessSet mode, MutatorFaultContext context);
 extern Res PoolWhiten(Pool pool, Trace trace, Seg seg);
 extern void PoolGrey(Pool pool, Trace trace, Seg seg);
 extern void PoolBlacken(Pool pool, TraceSet traceSet, Seg seg);
@@ -313,8 +314,10 @@ extern Res PoolNoDescribe(Pool pool, mps_lib_FILE *stream);
 extern Res PoolTrivDescribe(Pool pool, mps_lib_FILE *stream);
 extern Res PoolNoTraceBegin(Pool pool, Trace trace);
 extern Res PoolTrivTraceBegin(Pool pool, Trace trace);
-extern Res PoolNoAccess(Pool pool, Seg seg, Addr addr, AccessSet mode);
-extern Res PoolSegAccess(Pool pool, Seg seg, Addr addr, AccessSet mode);
+extern Res PoolNoAccess(Pool pool, Seg seg, Addr addr,
+                        AccessSet mode, MutatorFaultContext context);
+extern Res PoolSegAccess(Pool pool, Seg seg, Addr addr,
+                         AccessSet mode, MutatorFaultContext context);
 extern Res PoolNoWhiten(Pool pool, Trace trace, Seg seg);
 extern Res PoolTrivWhiten(Pool pool, Trace trace, Seg seg);
 extern void PoolNoGrey(Pool pool, Trace trace, Seg seg);
diff --git a/mps/src/mpmtypes.h b/mps/src/mpmtypes.h
index 88e149b5edd..201828db194 100644
--- a/mps/src/mpmtypes.h
+++ b/mps/src/mpmtypes.h
@@ -1,6 +1,6 @@
 /* impl.h.mpmtypes: MEMORY POOL MANAGER TYPES
  *
- * $HopeName: MMsrc!mpmtypes.h(trunk.45) $
+ * $HopeName: MMsrc!mpmtypes.h(trunk.46) $
  * Copyright (C) 1997 The Harlequin Group Limited.  All rights reserved.
  *
  * .readership: MM developers.
@@ -129,7 +129,7 @@ typedef void (*PoolBufferEmptyMethod)(Pool pool, Buffer buffer);
 typedef void (*PoolBufferFinishMethod)(Pool pool, Buffer buf);
 typedef Res (*PoolTraceBeginMethod)(Pool pool, Trace trace);
 typedef Res (*PoolAccessMethod)(Pool pool, Seg seg, Addr addr,
-			        AccessSet mode);
+			        AccessSet mode, MutatorFaultContext context);
 typedef Res (*PoolWhitenMethod)(Pool pool, Trace trace, Seg seg);
 typedef void (*PoolGreyMethod)(Pool pool, Trace trace, Seg seg);
 typedef void (*PoolBlackenMethod)(Pool pool, TraceSet traceSet, Seg seg);
diff --git a/mps/src/pool.c b/mps/src/pool.c
index c2d84eac59a..8c541c7aa3e 100644
--- a/mps/src/pool.c
+++ b/mps/src/pool.c
@@ -1,6 +1,6 @@
 /* impl.c.pool: POOL IMPLEMENTATION
  *
- * $HopeName: MMsrc!pool.c(trunk.49) $
+ * $HopeName: MMsrc!pool.c(trunk.50) $
  * Copyright (C) 1997. Harlequin Group plc. All rights reserved.
  *
  * READERSHIP
@@ -37,7 +37,7 @@
 
 #include "mpm.h"
 
-SRCID(pool, "$HopeName: MMsrc!pool.c(trunk.49) $");
+SRCID(pool, "$HopeName: MMsrc!pool.c(trunk.50) $");
 
 
 Bool PoolClassCheck(PoolClass class)
@@ -301,15 +301,17 @@ Res PoolTraceBegin(Pool pool, Trace trace)
   return (*pool->class->traceBegin)(pool, trace);
 }
 
-Res PoolAccess(Pool pool, Seg seg, Addr addr, AccessSet mode)
+Res PoolAccess(Pool pool, Seg seg, Addr addr,
+               AccessSet mode, MutatorFaultContext context)
 {
   AVERT(Pool, pool);
   AVERT(Seg, seg);
   AVER(SegBase(seg) <= addr);
   AVER(addr < SegLimit(seg));
   /* Can't check mode as there is no check method */
+  /* Can't check MutatorFaultContext as there is no check method */
 
-  return (*pool->class->access)(pool, seg, addr, mode);
+  return (*pool->class->access)(pool, seg, addr, mode, context);
 }
 
 Res PoolWhiten(Pool pool, Trace trace, Seg seg)
@@ -734,14 +736,17 @@ Res PoolTrivTraceBegin(Pool pool, Trace trace)
  * That is, no protected pages, or only pages which are inaccessible
  * by the mutator are protected.
  */
-Res PoolNoAccess(Pool pool, Seg seg, Addr addr, AccessSet mode)
+Res PoolNoAccess(Pool pool, Seg seg, Addr addr,
+                 AccessSet mode, MutatorFaultContext context)
 {
   AVERT(Pool, pool);
   AVERT(Seg, seg);
   AVER(SegBase(seg) <= addr);
   AVER(addr < SegLimit(seg));
   /* can't check AccessSet as there is no Check method */
+  /* can't check context as there is no Check method */
   UNUSED(mode);
+  UNUSED(context);
 
   NOTREACHED;
   return ResUNIMPL;
@@ -753,7 +758,8 @@ Res PoolNoAccess(Pool pool, Seg seg, Addr addr, AccessSet mode)
  * to handle page faults by scanning the entire segment and lowering
  * the barrier.
  */
-Res PoolSegAccess(Pool pool, Seg seg, Addr addr, AccessSet mode)
+Res PoolSegAccess(Pool pool, Seg seg, Addr addr,
+                  AccessSet mode, MutatorFaultContext context)
 {
   AVERT(Pool, pool);
   AVERT(Seg, seg);
@@ -763,7 +769,7 @@ Res PoolSegAccess(Pool pool, Seg seg, Addr addr, AccessSet mode)
   /* can't check AccessSet as there is no Check method */
 
   UNUSED(addr);
-  UNUSED(pool);
+  UNUSED(context);
   TraceSegAccess(PoolArena(pool), seg, mode);
   return ResOK;
 }