diff --git a/internal/sm2ec/p256_asm_s390x.s b/internal/sm2ec/p256_asm_s390x.s
index 55212dd..64c5632 100644
--- a/internal/sm2ec/p256_asm_s390x.s
+++ b/internal/sm2ec/p256_asm_s390x.s
@@ -276,7 +276,9 @@ loop_select:
 	VAB  SEL2, ONE, SEL2
 	ADD  $96, P1ptr
 	ADD  $1, COUNT
-	CMPBNE  COUNT, LIMIT, loop_select
+	//CMPBNE  COUNT, LIMIT, loop_select
+	CMPW COUNT, $33
+	BLT  loop_select
 
 	VST X1H, 0(P3ptr)
 	VST X1L, 16(P3ptr)