diff --git a/include/gmssl/zuc.h b/include/gmssl/zuc.h
index 20024266..96542ae1 100644
--- a/include/gmssl/zuc.h
+++ b/include/gmssl/zuc.h
@@ -112,7 +112,7 @@ typedef struct ZUC256_MAC_CTX_st {
 	ZUC_UINT32 T[4];
 	ZUC_UINT32 K0[4];
 	uint8_t buf[4];
-	int buflen;
+	size_t buflen;
 	int macbits;
 } ZUC256_MAC_CTX;
 
diff --git a/src/zuc.c b/src/zuc.c
index 0a09a9d7..fafbb025 100644
--- a/src/zuc.c
+++ b/src/zuc.c
@@ -88,20 +88,20 @@ static const uint8_t S1[256] = {
 	{int j; for (j=0; j<15;j++) LFSR[j]=LFSR[j+1];}	\
 	LFSR[15] = V
 
-#define LFSRWithWorkMode()			\
-	{					\
-	int j;					\
-	uint64_t a = LFSR[0];			\
-	a += ((uint64_t)LFSR[0]) << 8;		\
-	a += ((uint64_t)LFSR[4]) << 20;		\
-	a += ((uint64_t)LFSR[10]) << 21;	\
-	a += ((uint64_t)LFSR[13]) << 17;	\
-	a += ((uint64_t)LFSR[15]) << 15;	\
-	a = (a & 0x7fffffff) + (a >> 31);	\
-	V = (a & 0x7fffffff) + (a >> 31);	\
-	for (j = 0; j < 15; j++)		\
-		LFSR[j] = LFSR[j+1];		\
-	LFSR[15] = V;				\
+#define LFSRWithWorkMode()				\
+	{						\
+	int j;						\
+	uint64_t a = LFSR[0];				\
+	a += ((uint64_t)LFSR[0]) << 8;			\
+	a += ((uint64_t)LFSR[4]) << 20;			\
+	a += ((uint64_t)LFSR[10]) << 21;		\
+	a += ((uint64_t)LFSR[13]) << 17;		\
+	a += ((uint64_t)LFSR[15]) << 15;		\
+	a = (a & 0x7fffffff) + (a >> 31);		\
+	V = (uint32_t)((a & 0x7fffffff) + (a >> 31));	\
+	for (j = 0; j < 15; j++)			\
+		LFSR[j] = LFSR[j+1];			\
+	LFSR[15] = V;					\
 	}
 
 #define BitReconstruction2(X1,X2)					\
diff --git a/src/zuc_modes.c b/src/zuc_modes.c
index 80a620dc..ab386742 100644
--- a/src/zuc_modes.c
+++ b/src/zuc_modes.c
@@ -131,7 +131,6 @@ int zuc_encrypt_update(ZUC_CTX *ctx, const uint8_t *in, size_t inlen, uint8_t *o
 
 int zuc_encrypt_finish(ZUC_CTX *ctx, uint8_t *out, size_t *outlen)
 {
-	size_t left;
 	if (ctx->block_nbytes >= ZUC_BLOCK_SIZE) {
 		error_print();
 		return -1;