diff --git a/src/lj_opt_fold.c b/src/lj_opt_fold.c
index 470b6d44..e595d512 100644
--- a/src/lj_opt_fold.c
+++ b/src/lj_opt_fold.c
@@ -1700,7 +1700,8 @@ LJFOLD(ABC any any)
 LJFOLDF(abc_invar)
 {
   /* Invariant ABC marked as PTR. Drop if op1 is invariant, too. */
-  if (!irt_isint(fins->t) && fins->op1 < J->chain[IR_LOOP])
+  if (!irt_isint(fins->t) && fins->op1 < J->chain[IR_LOOP] &&
+      !irt_isphi(IR(fins->op1)->t))
     return DROPFOLD;
   return NEXTFOLD;
 }