diff --git a/demos/src/demo_sm2_keyparse.c b/demos/src/demo_sm2_keyparse.c
index cc69de97..c9f79055 100644
--- a/demos/src/demo_sm2_keyparse.c
+++ b/demos/src/demo_sm2_keyparse.c
@@ -17,7 +17,6 @@
 int main(int argc, char **argv)
 {
 	uint8_t buf[4096];
-	ssize_t len;
 	uint8_t dgst[32];
 	int i;
 
diff --git a/demos/src/demo_sm3.c b/demos/src/demo_sm3.c
index 2844d348..2e876dd5 100644
--- a/demos/src/demo_sm3.c
+++ b/demos/src/demo_sm3.c
@@ -18,7 +18,7 @@ int main(int argc, char **argv)
 {
 	SM3_CTX sm3_ctx;
 	uint8_t buf[4096];
-	ssize_t len;
+	size_t len;
 	uint8_t dgst[32];
 	int i;
 
diff --git a/demos/src/demo_sm4_cbc_decrypt_update.c b/demos/src/demo_sm4_cbc_decrypt_update.c
index f75a582b..e32333d4 100644
--- a/demos/src/demo_sm4_cbc_decrypt_update.c
+++ b/demos/src/demo_sm4_cbc_decrypt_update.c
@@ -27,7 +27,7 @@ int main(void)
 	};
 	unsigned char inbuf[1024];
 	unsigned char outbuf[1024 + 32];
-	ssize_t inlen;
+	size_t inlen;
 	size_t outlen;
 
 	if (sm4_cbc_decrypt_init(&cbc_ctx, key, iv) != 1) {
diff --git a/demos/src/demo_sm4_cbc_encrypt_update.c b/demos/src/demo_sm4_cbc_encrypt_update.c
index 21a51981..4e97d62f 100644
--- a/demos/src/demo_sm4_cbc_encrypt_update.c
+++ b/demos/src/demo_sm4_cbc_encrypt_update.c
@@ -27,7 +27,7 @@ int main(void)
 	};
 	unsigned char inbuf[1024];
 	unsigned char outbuf[1024 + 32];
-	ssize_t inlen;
+	size_t inlen;
 	size_t outlen;
 
 	if (sm4_cbc_encrypt_init(&cbc_ctx, key, iv) != 1) {
diff --git a/demos/src/demo_sm4_ctr_encrypt_update.c b/demos/src/demo_sm4_ctr_encrypt_update.c
index 947edcd7..1d580f65 100644
--- a/demos/src/demo_sm4_ctr_encrypt_update.c
+++ b/demos/src/demo_sm4_ctr_encrypt_update.c
@@ -27,7 +27,7 @@ int main(void)
 	};
 	unsigned char inbuf[1024];
 	unsigned char outbuf[1024 + 32];
-	ssize_t inlen;
+	size_t inlen;
 	size_t outlen;
 
 	if (sm4_ctr_encrypt_init(&cbc_ctx, key, ctr) != 1) {
diff --git a/demos/src/demo_zuc.c b/demos/src/demo_zuc.c
index af383117..6838ce12 100644
--- a/demos/src/demo_zuc.c
+++ b/demos/src/demo_zuc.c
@@ -26,7 +26,7 @@ int main(void)
 	};
 	unsigned char inbuf[1024];
 	unsigned char outbuf[1024 + 32];
-	ssize_t inlen;
+	size_t inlen;
 	size_t outlen;
 
 	if (zuc_encrypt_init(&zuc_ctx, key, iv) != 1) {
diff --git a/src/x509_ext.c b/src/x509_ext.c
index f1097471..4e765db7 100644
--- a/src/x509_ext.c
+++ b/src/x509_ext.c
@@ -2567,7 +2567,6 @@ int x509_revoke_reason_flags_print(FILE *fp, int fmt, int ind, const char *label
 int x509_uri_as_distribution_point_name_to_der(const char *uri, size_t urilen,
 	uint8_t **out, size_t *outlen)
 {
-	int ret;
 	int tag = ASN1_TAG_EXPLICIT(X509_full_name);
 
 	if (urilen == 0) {
diff --git a/tests/asn1test.c b/tests/asn1test.c
index 0ed5ce79..4bbcff2e 100644
--- a/tests/asn1test.c
+++ b/tests/asn1test.c
@@ -722,7 +722,6 @@ static int test_asn1_from_der_null_args(void)
 
 	int val;
 	const char *str;
-	const uint8_t *d;
 	size_t dlen;
 	time_t t;
 	uint32_t nodes[32];
diff --git a/tests/cmstest.c b/tests/cmstest.c
index 660d0881..4561e244 100644
--- a/tests/cmstest.c
+++ b/tests/cmstest.c
@@ -758,7 +758,6 @@ int test_cms_enveloped_data(void)
 	uint8_t in[80];
 	uint8_t out[256];
 	size_t outlen;
-	size_t maxlen;
 
 	uint8_t buf[4096];
 	uint8_t *p;
diff --git a/tools/crlverify.c b/tools/crlverify.c
index f22989b2..d42761d4 100644
--- a/tools/crlverify.c
+++ b/tools/crlverify.c
@@ -48,9 +48,6 @@ int crlverify_main(int argc, char **argv)
 	size_t cacertlen;
 	char signer_id[SM2_MAX_ID_LENGTH + 1] = SM2_DEFAULT_ID;
 	size_t signer_id_len = strlen(SM2_DEFAULT_ID);
-
-	const uint8_t *subject;
-	size_t subject_len;
 	int rv;
 
 	argc--;