diff --git a/common.c b/common.c
index d17c14d..b04066a 100644
--- a/common.c
+++ b/common.c
@@ -391,7 +391,7 @@ int connect_addr(struct connection *cnx, int fd_from, connect_blocking blocking)
 }
 
 /* Store some data to write to the queue later */
-int defer_write(struct queue *q, void* data, int data_size)
+int defer_write(struct queue *q, void* data, ssize_t data_size)
 {
     char *p;
     ptrdiff_t data_offset = q->deferred_data - q->begin_deferred_data;
@@ -403,7 +403,7 @@ int defer_write(struct queue *q, void* data, int data_size)
     q->begin_deferred_data = p;
     q->deferred_data = p + data_offset;
     p += data_offset + q->deferred_data_size;
-    q->deferred_data_size += data_size;
+    q->deferred_data_size += (int)data_size;
     memcpy(p, data, data_size);
 
     return 0;
@@ -415,13 +415,13 @@ int defer_write(struct queue *q, void* data, int data_size)
  * */
 int flush_deferred(struct queue *q)
 {
-    int n;
+    ssize_t n;
 
     print_message(msg_fd, "flushing deferred data to fd %d\n", q->fd);
 
     n = write(q->fd, q->deferred_data, q->deferred_data_size);
     if (n == -1)
-        return n;
+        return (int)n;
 
     if (n == q->deferred_data_size) {
         /* All has been written -- release the memory */
@@ -432,10 +432,10 @@ int flush_deferred(struct queue *q)
     } else {
         /* There is data left */
         q->deferred_data += n;
-        q->deferred_data_size -= n;
+        q->deferred_data_size -= (int)n;
     }
 
-    return n;
+    return (int)n;
 }
 
 
@@ -470,7 +470,8 @@ void dump_connection(struct connection *cnx)
 int fd2fd(struct queue *target_q, struct queue *from_q)
 {
    char buffer[BUFSIZ];
-   int target, from, size_r, size_w;
+   int target, from;
+   ssize_t size_r, size_w;
 
    target = target_q->fd;
    from = from_q->fd;
@@ -515,7 +516,7 @@ int fd2fd(struct queue *target_q, struct queue *from_q)
 
    CHECK_RES_RETURN(size_w, "write", FD_CNXCLOSED);
 
-   return size_w;
+   return (int)size_w;
 }
 
 /* returns a string that prints the IP and port of the sockaddr */
diff --git a/common.h b/common.h
index f94b743..9dc1c91 100644
--- a/common.h
+++ b/common.h
@@ -172,7 +172,7 @@ int resolve_split_name(struct addrinfo **out, char* hostname, char* port);
 
 int start_listen_sockets(struct listen_endpoint *sockfd[]);
 
-int defer_write(struct queue *q, void* data, int data_size);
+int defer_write(struct queue *q, void* data, ssize_t data_size);
 int flush_deferred(struct queue *q);
 
 extern struct sslhcfg_item cfg;
diff --git a/sslh-main.c b/sslh-main.c
index 9b02835..b427dac 100644
--- a/sslh-main.c
+++ b/sslh-main.c
@@ -69,7 +69,7 @@ static void printsettings(void)
         strcpy(buf, "resolve on forward");
         if (!p->resolve_on_forward) {
             sprintaddr(buf, sizeof(buf), p->saddr);
-            int len = strlen(buf);
+            size_t len = strlen(buf);
             sprintf(buf+len, " family %d %d", 
                     p->saddr->ai_family,
                     p->saddr->ai_addr->sa_family);
@@ -98,7 +98,8 @@ static void printsettings(void)
 static void setup_regex_probe(struct sslhcfg_protocols_item *p)
 #ifdef ENABLE_REGEX
 {
-    int num_patterns, i, error;
+    size_t num_patterns, i;
+    int error;
     pcre2_code** pattern_list;
     PCRE2_SIZE error_offset;
     PCRE2_UCHAR8 err_str[120];
@@ -186,7 +187,7 @@ void config_sanity_check(struct sslhcfg_item* cfg)
 #endif
 
     for (i = 0; i < cfg->protocols_len; ++i) {
-        if (strcmp(cfg->protocols[i].name, "tls")) {
+        if (strcmp(cfg->protocols[i].name, "tls") != 0) {
             if (cfg->protocols[i].sni_hostnames_len) {
                 print_message(msg_config_error, "name: \"%s\"; host: \"%s\"; port: \"%s\": "
                               "Config option sni_hostnames is only applicable for tls\n",
diff --git a/tls.c b/tls.c
index bf0101d..5a0e64a 100644
--- a/tls.c
+++ b/tls.c
@@ -224,7 +224,7 @@ parse_server_name_extension(const struct TLSProtocol *tls_data, const char *data
         switch (data[pos]) { /* name type */
             case 0x00: /* host_name */
                 if(has_match(tls_data->sni_hostname_list, tls_data->sni_list_len, data + pos + 3, len)) {
-                    return len;
+                    return (int)len;
                 } else {
                     return TLS_ENOEXT;
                 }
@@ -253,7 +253,7 @@ parse_alpn_extension(const struct TLSProtocol *tls_data, const char *data, size_
             return TLS_EPROTOCOL;
 
         if (len > 0 && has_match(tls_data->alpn_protocol_list, tls_data->alpn_list_len, data + pos + 1, len)) {
-            return len;
+            return (int)len;
         } else if (len > 0) {
             print_message(msg_probe_error, "Unknown ALPN name: %.*s\n", (int)len, data + pos + 1);
         }
@@ -301,11 +301,11 @@ struct TLSProtocol *
 tls_data_set_list(struct TLSProtocol *tls_data, int alpn, const char** list, size_t list_len) {
     if (alpn) {
         tls_data->alpn_protocol_list = list;
-        tls_data->alpn_list_len = list_len;
+        tls_data->alpn_list_len = (int)list_len;
         tls_data->match_mode.tls_match_alpn = 1;
     } else {
         tls_data->sni_hostname_list = list;
-        tls_data->sni_list_len = list_len;
+        tls_data->sni_list_len = (int)list_len;
         tls_data->match_mode.tls_match_sni = 1;
     }
 
diff --git a/udp-listener.c b/udp-listener.c
index d3f5590..720cc94 100644
--- a/udp-listener.c
+++ b/udp-listener.c
@@ -259,7 +259,8 @@ struct connection* udp_c2s_forward(int sockfd, struct loop_info* fd_info)
     struct connection* cnx;
     ssize_t len;
     socklen_t addrlen;
-    int res, target, out = -1;
+    ssize_t res;
+    int target, out = -1;
     char data[65536]; /* Theoretical max is 65507 (https://en.wikipedia.org/wiki/User_Datagram_Protocol).
                          This will do.  Dynamic allocation is possible with the MSG_PEEK flag in recvfrom(2), but that'd imply
                          malloc/free overhead for each packet, when really 64K is not that much */
@@ -280,7 +281,7 @@ struct connection* udp_c2s_forward(int sockfd, struct loop_info* fd_info)
                   len, target, sprintaddr(addr_str, sizeof(addr_str), &addrinfo));
 
     if (target == -1) {
-        res = probe_buffer(data, len, udp_protocols, udp_protocols_len, &proto);
+        res = probe_buffer(data, (int)len, udp_protocols, udp_protocols_len, &proto);
         /* First version: if we can't work out the protocol from the first
          * packet, drop it. Conceivably, we could store several packets to
          * run probes on packet sets */
@@ -324,7 +325,7 @@ void udp_s2c_forward(struct connection* cnx)
 {
     int sockfd = cnx->target_sock;
     char data[65536];
-    int res;
+    ssize_t res;
 
     res = recvfrom(sockfd, data, sizeof(data), 0, NULL, NULL);
     if ((res == -1) && ((errno == EAGAIN) || (errno == EWOULDBLOCK))) return;