diff --git a/lib/loop.c b/lib/loop.c
index 24ec984a..00b99ee3 100644
--- a/lib/loop.c
+++ b/lib/loop.c
@@ -103,7 +103,7 @@ int mosquitto_loop(struct mosquitto *mosq, int timeout, int max_packets)
 		/* sockpairR is used to break out of select() before the timeout, on a
 		 * call to publish() etc. */
 		FD_SET(mosq->sockpairR, &readfds);
-		if(mosq->sockpairR > maxfd){
+		if((int)mosq->sockpairR > maxfd){
 			maxfd = mosq->sockpairR;
 		}
 	}
@@ -246,7 +246,7 @@ static int interruptible_sleep(struct mosquitto *mosq, time_t reconnect_delay)
 int mosquitto_loop_forever(struct mosquitto *mosq, int timeout, int max_packets)
 {
 	int run = 1;
-	int rc;
+	int rc = MOSQ_ERR_SUCCESS;
 	unsigned long reconnect_delay;
 	enum mosquitto_client_state state;
 
@@ -361,7 +361,7 @@ static int mosquitto__loop_rc_handle(struct mosquitto *mosq, int rc)
 
 int mosquitto_loop_read(struct mosquitto *mosq, int max_packets)
 {
-	int rc;
+	int rc = MOSQ_ERR_SUCCESS;
 	int i;
 	if(max_packets < 1) return MOSQ_ERR_INVAL;
 
@@ -402,7 +402,7 @@ int mosquitto_loop_read(struct mosquitto *mosq, int max_packets)
 
 int mosquitto_loop_write(struct mosquitto *mosq, int max_packets)
 {
-	int rc;
+	int rc = MOSQ_ERR_SUCCESS;
 	int i;
 	if(max_packets < 1) return MOSQ_ERR_INVAL;
 
diff --git a/lib/misc_mosq.c b/lib/misc_mosq.c
index f092527f..75b2eaac 100644
--- a/lib/misc_mosq.c
+++ b/lib/misc_mosq.c
@@ -52,7 +52,7 @@ FILE *mosquitto__fopen(const char *path, const char *mode, bool restrict_read)
 			EXPLICIT_ACCESS_A ea;
 			PACL pacl = NULL;
 			char username[UNLEN + 1];
-			int ulen = UNLEN;
+			DWORD ulen = UNLEN;
 			SECURITY_DESCRIPTOR sd;
 			DWORD dwCreationDisposition;
 
diff --git a/lib/mosquitto.c b/lib/mosquitto.c
index 2af233d7..52fd30da 100644
--- a/lib/mosquitto.c
+++ b/lib/mosquitto.c
@@ -58,7 +58,7 @@ int mosquitto_lib_init(void)
 
 	if (init_refcount == 0) {
 #ifdef WIN32
-		srand(GetTickCount64());
+		srand((unsigned int)GetTickCount64());
 #elif _POSIX_TIMERS>0 && defined(_POSIX_MONOTONIC_CLOCK)
 		struct timespec tp;
 
@@ -348,7 +348,7 @@ int mosquitto_sub_topic_tokenise(const char *subtopic, char ***topics, int *coun
 	size_t len;
 	size_t hier_count = 1;
 	size_t start, stop;
-	int hier;
+	size_t hier;
 	size_t tlen;
 	size_t i, j;
 
diff --git a/lib/net_mosq.c b/lib/net_mosq.c
index 0d961a46..1000d4ed 100644
--- a/lib/net_mosq.c
+++ b/lib/net_mosq.c
@@ -397,6 +397,8 @@ static int net__try_connect_tcp(const char *host, uint16_t port, mosq_sock_t *so
 	uint32_t val = 1;
 #endif
 
+	ainfo_bind = NULL;
+
 	*sock = INVALID_SOCKET;
 	memset(&hints, 0, sizeof(struct addrinfo));
 	hints.ai_family = AF_UNSPEC;
@@ -926,7 +928,7 @@ int net__socket_connect(struct mosquitto *mosq, const char *host, uint16_t port,
 
 	if(mosq->tcp_nodelay){
 		int flag = 1;
-		if(setsockopt(mosq->sock, IPPROTO_TCP, TCP_NODELAY, &flag, sizeof(int)) != 0){
+		if(setsockopt(mosq->sock, IPPROTO_TCP, TCP_NODELAY, (const void*)&flag, sizeof(int)) != 0){
 			log__printf(mosq, MOSQ_LOG_WARNING, "Warning: Unable to set TCP_NODELAY.");
 		}
 	}
diff --git a/lib/send_connect.c b/lib/send_connect.c
index 65a5b3ee..29b29c69 100644
--- a/lib/send_connect.c
+++ b/lib/send_connect.c
@@ -143,9 +143,9 @@ int send__connect(struct mosquitto *mosq, uint16_t keepalive, bool clean_session
 
 	/* Variable header */
 	if(version == MQTT_PROTOCOL_V31){
-		packet__write_string(packet, PROTOCOL_NAME_v31, strlen(PROTOCOL_NAME_v31));
+		packet__write_string(packet, PROTOCOL_NAME_v31, (uint16_t)strlen(PROTOCOL_NAME_v31));
 	}else{
-		packet__write_string(packet, PROTOCOL_NAME, strlen(PROTOCOL_NAME));
+		packet__write_string(packet, PROTOCOL_NAME, (uint16_t)strlen(PROTOCOL_NAME));
 	}
 #if defined(WITH_BROKER) && defined(WITH_BRIDGE)
 	if(mosq->bridge && mosq->bridge->protocol_version != mosq_p_mqtt5 && mosq->bridge->try_private && mosq->bridge->try_private_accepted){