diff --git a/internal/sm2ec/sm2p256_asm_ppc64le_test.go b/internal/sm2ec/sm2p256_asm_ppc64le_test.go
index 3632e0e..388e61e 100644
--- a/internal/sm2ec/sm2p256_asm_ppc64le_test.go
+++ b/internal/sm2ec/sm2p256_asm_ppc64le_test.go
@@ -66,11 +66,10 @@ func testP256OrderReduce(v *big.Int, t *testing.T) {
 	montFromBig((*[4]uint64)(val), v)
 	p256OrdReduce(val)
 	if ordElmToBigInt(val).Cmp(v) != 0 {
-		t.Fatalf("p256OrdReduce failed for %v", v)
+		t.Fatalf("p256OrdReduce failed for %x, got %x", v.Bytes(), ordElmToBigInt(val).Bytes())
 	}
 }
 
-
 func TestP256OrderReduce(t *testing.T) {
 	p, _ := new(big.Int).SetString("FFFFFFFEFFFFFFFFFFFFFFFFFFFFFFFF7203DF6B21C6052B53BBF40939D54123", 16)
 	for i := 0; i < 20; i++ {