diff --git a/library/ssl_misc.h b/library/ssl_misc.h
index c636ad4..eae192b 100644
--- a/library/ssl_misc.h
+++ b/library/ssl_misc.h
@@ -1409,7 +1409,7 @@
  * Write handshake message header
  */
 MBEDTLS_CHECK_RETURN_CRITICAL
-int mbedtls_ssl_start_handshake_msg(mbedtls_ssl_context *ssl, unsigned hs_type,
+int mbedtls_ssl_start_handshake_msg(mbedtls_ssl_context *ssl, unsigned char hs_type,
                                     unsigned char **buf, size_t *buf_len);
 
 MBEDTLS_CHECK_RETURN_CRITICAL
diff --git a/library/ssl_msg.c b/library/ssl_msg.c
index 065336b..48d0a03 100644
--- a/library/ssl_msg.c
+++ b/library/ssl_msg.c
@@ -2731,7 +2731,7 @@
 /*
  * Handshake layer functions
  */
-int mbedtls_ssl_start_handshake_msg(mbedtls_ssl_context *ssl, unsigned hs_type,
+int mbedtls_ssl_start_handshake_msg(mbedtls_ssl_context *ssl, unsigned char hs_type,
                                     unsigned char **buf, size_t *buf_len)
 {
     /*
diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index 0ba9235..036b37a 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -4466,7 +4466,7 @@
     }
 
 #if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
-    used += 2 + ssl->transform->in_cid_len + ssl->transform->out_cid_len;
+    used += 2U + ssl->transform->in_cid_len + ssl->transform->out_cid_len;
     if (used <= buf_len) {
         *p++ = ssl->transform->in_cid_len;
         memcpy(p, ssl->transform->in_cid, ssl->transform->in_cid_len);
@@ -5692,7 +5692,7 @@
                                  uint32_t *flags)
 {
     int ret = 0;
-    int usage = 0;
+    unsigned int usage = 0;
     const char *ext_oid;
     size_t ext_len;
 
@@ -7665,7 +7665,7 @@
                                          unsigned char *padbuf, size_t hlen,
                                          unsigned char *buf, int from)
 {
-    int len = 12;
+    unsigned int len = 12;
     const char *sender;
 #if defined(MBEDTLS_USE_PSA_CRYPTO)
     psa_status_t status;
@@ -7865,7 +7865,8 @@
 
 int mbedtls_ssl_write_finished(mbedtls_ssl_context *ssl)
 {
-    int ret, hash_len;
+    int ret;
+    unsigned int hash_len;
 
     MBEDTLS_SSL_DEBUG_MSG(2, ("=> write finished"));
 
diff --git a/library/ssl_tls12_server.c b/library/ssl_tls12_server.c
index d3cb629..a07d0fb 100644
--- a/library/ssl_tls12_server.c
+++ b/library/ssl_tls12_server.c
@@ -3099,8 +3099,8 @@
         mbedtls_pk_type_t sig_alg =
             mbedtls_ssl_get_ciphersuite_sig_pk_alg(ciphersuite_info);
 
-        unsigned int sig_hash =
-            mbedtls_ssl_tls12_get_preferred_hash_for_sig_alg(
+        unsigned char sig_hash =
+            (unsigned char) mbedtls_ssl_tls12_get_preferred_hash_for_sig_alg(
                 ssl, mbedtls_ssl_sig_from_pk_alg(sig_alg));
 
         mbedtls_md_type_t md_alg = mbedtls_ssl_md_alg_from_hash(sig_hash);