diff --git a/src/lj_dispatch.c b/src/lj_dispatch.c
index b427a06e..3ce09371 100644
--- a/src/lj_dispatch.c
+++ b/src/lj_dispatch.c
@@ -264,8 +264,9 @@ void lj_dispatch_ins(lua_State *L, const BCIns *pc, uint32_t nres)
   GCproto *pt = funcproto(fn);
   BCReg slots = cur_topslot(pt, pc, nres);
   global_State *g = G(L);
-  const BCIns *oldpc = cframe_Lpc(L);
-  cframe_Lpc(L) = pc;
+  void *cf = cframe_raw(L->cframe);
+  const BCIns *oldpc = cframe_pc(cf);
+  setcframe_pc(cf, pc);
   L->top = L->base + slots;  /* Fix top. */
 #if LJ_HASJIT
   {
diff --git a/src/lj_frame.h b/src/lj_frame.h
index 1c03e3e1..14d640cd 100644
--- a/src/lj_frame.h
+++ b/src/lj_frame.h
@@ -58,12 +58,28 @@ enum {
 
 /* These definitions must match with the arch-specific *.dasc files. */
 #if LJ_TARGET_X86
-#define CFRAME_OFS_ERRF		(15*sizeof(void *))
-#define CFRAME_OFS_NRES		(14*sizeof(void *))
-#define CFRAME_OFS_PREV		(13*sizeof(void *))
-#define CFRAME_OFS_L		(12*sizeof(void *))
-#define CFRAME_OFS_PC		(6*sizeof(void *))
-#define CFRAME_SIZE		(12*sizeof(void *))
+#define CFRAME_OFS_ERRF		(15*4)
+#define CFRAME_OFS_NRES		(14*4)
+#define CFRAME_OFS_PREV		(13*4)
+#define CFRAME_OFS_L		(12*4)
+#define CFRAME_OFS_PC		(6*4)
+#define CFRAME_SIZE		(12*4)
+#elif LJ_TARGET_X64
+#if _WIN64
+#define CFRAME_OFS_ERRF		(23*4)
+#define CFRAME_OFS_NRES		(22*4)
+#define CFRAME_OFS_PREV		(13*8)
+#define CFRAME_OFS_L		(24*4)
+#define CFRAME_OFS_PC		(25*4)
+#define CFRAME_SIZE		(10*8)
+#else
+#define CFRAME_OFS_ERRF		(3*4)
+#define CFRAME_OFS_NRES		(2*4)
+#define CFRAME_OFS_PREV		(4*8)
+#define CFRAME_OFS_L		(4*4)
+#define CFRAME_OFS_PC		(5*4)
+#define CFRAME_SIZE		(10*8)
+#endif
 #else
 #error "Missing CFRAME_* definitions for this architecture"
 #endif
@@ -72,11 +88,15 @@ enum {
 #define CFRAME_CANYIELD		((intptr_t)(CFRAME_RESUME))
 #define CFRAME_RAWMASK		(~CFRAME_CANYIELD)
 
-#define cframe_errfunc(cf)	(*(ptrdiff_t *)(((char *)cf)+CFRAME_OFS_ERRF))
-#define cframe_nres(cf)		(*(ptrdiff_t *)(((char *)cf)+CFRAME_OFS_NRES))
-#define cframe_prev(cf)		(*(void **)(((char *)cf)+CFRAME_OFS_PREV))
-#define cframe_L(cf)		(*(lua_State **)(((char *)cf)+CFRAME_OFS_L))
-#define cframe_pc(cf)		(*(const BCIns **)(((char *)cf)+CFRAME_OFS_PC))
+#define cframe_errfunc(cf)	(*(int32_t *)(((char *)(cf))+CFRAME_OFS_ERRF))
+#define cframe_nres(cf)		(*(int32_t *)(((char *)(cf))+CFRAME_OFS_NRES))
+#define cframe_prev(cf)		(*(void **)(((char *)(cf))+CFRAME_OFS_PREV))
+#define cframe_L(cf) \
+  (&gcref(*(GCRef *)(((char *)(cf))+CFRAME_OFS_L))->th)
+#define cframe_pc(cf) \
+  (mref(*(MRef *)(((char *)(cf))+CFRAME_OFS_PC), const BCIns))
+#define setcframe_pc(cf, pc) \
+  (setmref(*(MRef *)(((char *)(cf))+CFRAME_OFS_PC), (pc)))
 #define cframe_canyield(cf)	((intptr_t)(cf) & CFRAME_CANYIELD)
 #define cframe_raw(cf)		((void *)((intptr_t)(cf) & CFRAME_RAWMASK))
 #define cframe_Lpc(L)		cframe_pc(cframe_raw(L->cframe))
diff --git a/src/lj_trace.c b/src/lj_trace.c
index 37d20328..8849b65c 100644
--- a/src/lj_trace.c
+++ b/src/lj_trace.c
@@ -572,7 +572,7 @@ void * LJ_FASTCALL lj_trace_exit(jit_State *J, void *exptr)
   /* Restore interpreter state. */
   lj_snap_restore(J, exptr);
   cf = cframe_raw(L->cframe);
-  cframe_pc(cf) = J->pc;
+  setcframe_pc(cf, J->pc);
 
   lj_vmevent_send(L, TEXIT,
     ExitState *ex = (ExitState *)exptr;