diff --git a/gcc/tree-parloops.cc b/gcc/tree-parloops.cc
index a35f3d5023b06e5ef96eb4222488fcb34dd7bd45..80f3dd6dce281e1eb1d76d38bd09e6638a875142 100644
--- a/gcc/tree-parloops.cc
+++ b/gcc/tree-parloops.cc
@@ -2531,14 +2531,15 @@ try_transform_to_exit_first_loop_alt (class loop *loop,
   tree nit_type = TREE_TYPE (nit);
 
   /* Figure out whether nit + 1 overflows.  */
-  if (TREE_CODE (nit) == INTEGER_CST)
+  if (poly_int_tree_p (nit))
     {
       if (!tree_int_cst_equal (nit, TYPE_MAX_VALUE (nit_type)))
 	{
 	  alt_bound = fold_build2_loc (UNKNOWN_LOCATION, PLUS_EXPR, nit_type,
 				       nit, build_one_cst (nit_type));
 
-	  gcc_assert (TREE_CODE (alt_bound) == INTEGER_CST);
+	  gcc_assert (TREE_CODE (alt_bound) == INTEGER_CST
+		      || TREE_CODE (alt_bound) == POLY_INT_CST);
 	  transform_to_exit_first_loop_alt (loop, reduction_list, alt_bound);
 	  return true;
 	}