diff --git a/src/lj_record.c b/src/lj_record.c
index 48bbbb20..6666b3c6 100644
--- a/src/lj_record.c
+++ b/src/lj_record.c
@@ -1025,7 +1025,9 @@ void lj_record_ret(jit_State *J, BCReg rbase, ptrdiff_t gotresults)
 	J->L->base = b + baseadj;
 	copyTV(J->L, b-(2<<LJ_FR2), &save);
       }
-      if (tr) {  /* Store final result. */
+      if (tr >= 0xffffff00) {
+	lj_err_throw(J->L, -(int32_t)tr);  /* Propagate errors. */
+      } else if (tr) {  /* Store final result. */
 	BCReg dst = bc_a(*(frame_contpc(frame)-1));
 	J->base[dst] = tr;
 	if (dst >= J->maxslot) {
@@ -2075,12 +2077,27 @@ static TRef rec_tnew(jit_State *J, uint32_t ah)
 
 /* -- Concatenation ------------------------------------------------------- */
 
+typedef struct RecCatDataCP {
+  jit_State *J;
+  RecordIndex *ix;
+} RecCatDataCP;
+
+static TValue *rec_mm_concat_cp(lua_State *L, lua_CFunction dummy, void *ud)
+{
+  RecCatDataCP *rcd = (RecCatDataCP *)ud;
+  UNUSED(L); UNUSED(dummy);
+  rec_mm_arith(rcd->J, rcd->ix, MM_concat);  /* Call __concat metamethod. */
+  return NULL;
+}
+
 static TRef rec_cat(jit_State *J, BCReg baseslot, BCReg topslot)
 {
   TRef *top = &J->base[topslot];
   TValue savetv[5+LJ_FR2];
   BCReg s;
   RecordIndex ix;
+  RecCatDataCP rcd;
+  int errcode;
   lj_assertJ(baseslot < topslot, "bad CAT arg");
   for (s = baseslot; s <= topslot; s++)
     (void)getslot(J, s);  /* Ensure all arguments have a reference. */
@@ -2116,8 +2133,11 @@ static TRef rec_cat(jit_State *J, BCReg baseslot, BCReg topslot)
   ix.tab = top[-1];
   ix.key = top[0];
   memcpy(savetv, &J->L->base[topslot-1], sizeof(savetv));  /* Save slots. */
-  rec_mm_arith(J, &ix, MM_concat);  /* Call __concat metamethod. */
+  rcd.J = J;
+  rcd.ix = &ix;
+  errcode = lj_vm_cpcall(J->L, NULL, &rcd, rec_mm_concat_cp);
   memcpy(&J->L->base[topslot-1], savetv, sizeof(savetv));  /* Restore slots. */
+  if (errcode) return (TRef)(-errcode);
   return 0;  /* No result yet. */
 }
 
@@ -2440,6 +2460,8 @@ void lj_record_ins(jit_State *J)
 
   case BC_CAT:
     rc = rec_cat(J, rb, rc);
+    if (rc >= 0xffffff00)
+      lj_err_throw(J->L, -(int32_t)rc);  /* Propagate errors. */
     break;
 
   /* -- Constant and move ops --------------------------------------------- */