diff --git a/include/gmssl/sm9_z256.h b/include/gmssl/sm9_z256.h
index 3506e1f4..e1899db0 100644
--- a/include/gmssl/sm9_z256.h
+++ b/include/gmssl/sm9_z256.h
@@ -71,7 +71,7 @@ void sm9_z256_fp_neg(sm9_z256_t r, const sm9_z256_t a);
 void sm9_z256_fp_mont_mul(sm9_z256_t r, const sm9_z256_t a, const sm9_z256_t b);
 void sm9_z256_fp_to_mont(sm9_z256_t r, const sm9_z256_t a);
 void sm9_z256_fp_from_mont(sm9_z256_t r, const sm9_z256_t a);
-#define sm9_z256_fp_sqr(r,a,b)	sm9_z256_fp_mont_sqr(r,a,b)
+#define sm9_z256_fp_sqr(r,a)	sm9_z256_fp_mont_sqr(r,a)
 void sm9_z256_fp_mont_sqr(sm9_z256_t r, const sm9_z256_t a);
 void sm9_z256_fp_pow(sm9_z256_t r, const sm9_z256_t a, const sm9_z256_t e);
 void sm9_z256_fp_inv(sm9_z256_t r, const sm9_z256_t a);