diff --git a/examples/mqtt-client/main.c b/examples/mqtt-client/main.c
index e041919f..2c5c9ff8 100644
--- a/examples/mqtt-client/main.c
+++ b/examples/mqtt-client/main.c
@@ -17,7 +17,9 @@ static const char *s_topic = "mg/mq-clnt-test";
 static int s_qos = 1;
 
 static void fn(struct mg_connection *c, int ev, void *ev_data, void *fn_data) {
-  if (ev == MG_EV_ERROR) {
+  if (ev == MG_EV_OPEN) {
+    // c->is_hexdumping = 1;
+  } else if (ev == MG_EV_ERROR) {
     // On error, log error message
     LOG(LL_ERROR, ("%p %s", c->fd, (char *) ev_data));
   } else if (ev == MG_EV_CONNECT) {
@@ -30,9 +32,9 @@ static void fn(struct mg_connection *c, int ev, void *ev_data, void *fn_data) {
     // MQTT connect is successful
     struct mg_str topic = mg_str(s_topic), data = mg_str("hello");
     LOG(LL_INFO, ("CONNECTED to %s", s_url));
-    mg_mqtt_sub(c, &topic, 1);
+    mg_mqtt_sub(c, &topic, s_qos);
     LOG(LL_INFO, ("SUBSCRIBED to %.*s", (int) topic.len, topic.ptr));
-    mg_mqtt_pub(c, &topic, &data, 1, false);
+    mg_mqtt_pub(c, &topic, &data, s_qos, false);
     LOG(LL_INFO, ("PUBSLISHED %.*s -> %.*s", (int) data.len, data.ptr,
                   (int) topic.len, topic.ptr));
   } else if (ev == MG_EV_MQTT_MSG) {
@@ -43,6 +45,7 @@ static void fn(struct mg_connection *c, int ev, void *ev_data, void *fn_data) {
   }
 
   if (ev == MG_EV_ERROR || ev == MG_EV_CLOSE || ev == MG_EV_MQTT_MSG) {
+    LOG(LL_INFO, ("Got event %d, stopping...", ev));
     *(bool *) fn_data = true;  // Signal that we're done
   }
 }
diff --git a/mongoose.c b/mongoose.c
index ab899350..42f30579 100644
--- a/mongoose.c
+++ b/mongoose.c
@@ -2094,8 +2094,6 @@ void mg_md5_final(mg_md5_ctx *ctx, unsigned char digest[16]) {
 #define MQTT_WILL_RETAIN 0x20
 #define MQTT_HAS_PASSWORD 0x40
 #define MQTT_HAS_USER_NAME 0x80
-#define MQTT_GET_WILL_QOS(flags) (((flags) &0x18) >> 3)
-#define MQTT_SET_WILL_QOS(flags, qos) (flags) = ((flags) & ~0x18) | ((qos) << 3)
 
 enum { MQTT_OK, MQTT_INCOMPLETE, MQTT_MALFORMED };
 
@@ -2117,34 +2115,43 @@ static void mg_send_u16(struct mg_connection *c, uint16_t value) {
 }
 
 void mg_mqtt_login(struct mg_connection *c, struct mg_mqtt_opts *opts) {
+  char rnd[9], client_id[16];
+  struct mg_str cid = opts->client_id;
   uint32_t total_len = 7 + 1 + 2 + 2;
-  uint16_t flags = (uint16_t) (((uint16_t) opts->qos & 3) << 3);
+  uint8_t connflag = (uint8_t) ((opts->qos & 3) << 1);
+
+  if (cid.len == 0) {
+    mg_random(rnd, sizeof(rnd));
+    mg_base64_encode((unsigned char *) rnd, sizeof(rnd), client_id);
+    client_id[sizeof(client_id) - 1] = '\0';
+    cid = mg_str(client_id);
+  }
 
   if (opts->user.len > 0) {
     total_len += 2 + (uint32_t) opts->user.len;
-    flags |= MQTT_HAS_USER_NAME;
+    connflag |= MQTT_HAS_USER_NAME;
   }
   if (opts->pass.len > 0) {
     total_len += 2 + (uint32_t) opts->pass.len;
-    flags |= MQTT_HAS_PASSWORD;
+    connflag |= MQTT_HAS_PASSWORD;
   }
   if (opts->will_topic.len > 0 && opts->will_message.len > 0) {
     total_len +=
         4 + (uint32_t) opts->will_topic.len + (uint32_t) opts->will_message.len;
-    flags |= MQTT_HAS_WILL;
+    connflag |= MQTT_HAS_WILL;
   }
-  if (opts->clean || opts->client_id.len == 0) flags |= MQTT_CLEAN_SESSION;
-  if (opts->will_retain) flags |= MQTT_WILL_RETAIN;
-  total_len += (uint32_t) opts->client_id.len;
+  if (opts->clean || cid.len == 0) connflag |= MQTT_CLEAN_SESSION;
+  if (opts->will_retain) connflag |= MQTT_WILL_RETAIN;
+  total_len += (uint32_t) cid.len;
 
   mg_mqtt_send_header(c, MQTT_CMD_CONNECT, 0, total_len);
   mg_send(c, "\00\04MQTT\04", 7);
-  mg_send(c, &flags, 1);
+  mg_send(c, &connflag, sizeof(connflag));
   // keepalive == 0 means "do not disconnect us!"
   mg_send_u16(c, mg_htons((uint16_t) opts->keepalive));
-  mg_send_u16(c, mg_htons((uint16_t) opts->client_id.len));
-  mg_send(c, opts->client_id.ptr, opts->client_id.len);
-  if (flags & MQTT_HAS_WILL) {
+  mg_send_u16(c, mg_htons((uint16_t) cid.len));
+  mg_send(c, cid.ptr, cid.len);
+  if (connflag & MQTT_HAS_WILL) {
     mg_send_u16(c, mg_htons((uint16_t) opts->will_topic.len));
     mg_send(c, opts->will_topic.ptr, opts->will_topic.len);
     mg_send_u16(c, mg_htons((uint16_t) opts->will_message.len));
@@ -2166,11 +2173,11 @@ void mg_mqtt_pub(struct mg_connection *c, struct mg_str *topic,
   uint32_t total_len = 2 + (uint32_t) topic->len + (uint32_t) data->len;
   LOG(LL_DEBUG, ("%lu [%.*s] -> [%.*s]", c->id, (int) topic->len,
                  (char *) topic->ptr, (int) data->len, (char *) data->ptr));
-  if (MQTT_GET_QOS(flags) > 0) total_len += 2;
+  if (qos > 0) total_len += 2;
   mg_mqtt_send_header(c, MQTT_CMD_PUBLISH, flags, total_len);
   mg_send_u16(c, mg_htons((uint16_t) topic->len));
   mg_send(c, topic->ptr, topic->len);
-  if (MQTT_GET_QOS(flags) > 0) {
+  if (qos > 0) {
     static uint16_t s_id;
     if (++s_id == 0) s_id++;
     mg_send_u16(c, mg_htons(s_id));
@@ -2182,8 +2189,7 @@ void mg_mqtt_sub(struct mg_connection *c, struct mg_str *topic, int qos) {
   static uint16_t s_id;
   uint8_t qos_ = qos & 3;
   uint32_t total_len = 2 + (uint32_t) topic->len + 2 + 1;
-  mg_mqtt_send_header(c, MQTT_CMD_SUBSCRIBE, (uint8_t) MQTT_QOS(qos_),
-                      total_len);
+  mg_mqtt_send_header(c, MQTT_CMD_SUBSCRIBE, 2, total_len);
   if (++s_id == 0) ++s_id;
   mg_send_u16(c, mg_htons(s_id));
   mg_send_u16(c, mg_htons((uint16_t) topic->len));
@@ -3222,6 +3228,7 @@ struct mg_connection *mg_connect(struct mg_mgr *mgr, const char *url,
     c->fn = fn;
     c->fn_data = fn_data;
     LOG(LL_DEBUG, ("%lu -> %s", c->id, url));
+    mg_call(c, MG_EV_OPEN, NULL);
     mg_resolve(c, &host, mgr->dnstimeout);
   }
   return c;
@@ -3262,6 +3269,7 @@ static void accept_conn(struct mg_mgr *mgr, struct mg_connection *lsn) {
     c->pfn_data = lsn->pfn_data;
     c->fn = lsn->fn;
     c->fn_data = lsn->fn_data;
+    mg_call(c, MG_EV_OPEN, NULL);
     mg_call(c, MG_EV_ACCEPT, NULL);
   }
 }
@@ -3322,6 +3330,7 @@ struct mg_connection *mg_mkpipe(struct mg_mgr *mgr, mg_event_handler_t fn,
     c->pfn_data = (void *) (size_t) sp[0];
     c->fn = fn;
     c->fn_data = fn_data;
+    mg_call(c, MG_EV_OPEN, NULL);
     LIST_ADD_HEAD(struct mg_connection, &mgr->conns, c);
   }
   return c;
@@ -3346,7 +3355,8 @@ struct mg_connection *mg_listen(struct mg_mgr *mgr, const char *url,
     LIST_ADD_HEAD(struct mg_connection, &mgr->conns, c);
     c->fn = fn;
     c->fn_data = fn_data;
-    LOG(LL_INFO,
+    mg_call(c, MG_EV_OPEN, NULL);
+    LOG(LL_DEBUG,
         ("%lu accepting on %s (port %u)", c->id, url, mg_ntohs(c->peer.port)));
   }
   return c;
diff --git a/mongoose.h b/mongoose.h
index db4fad1e..419f080c 100644
--- a/mongoose.h
+++ b/mongoose.h
@@ -737,6 +737,7 @@ void mg_error(struct mg_connection *c, const char *fmt, ...);
 
 enum {
   MG_EV_ERROR,       // Error                        char *error_message
+  MG_EV_OPEN,        // Connection created           NULL
   MG_EV_POLL,        // mg_mgr_poll iteration        unsigned long *millis
   MG_EV_RESOLVE,     // Host name is resolved        NULL
   MG_EV_CONNECT,     // Connection established       NULL
@@ -969,10 +970,6 @@ int mg_sntp_parse(const unsigned char *buf, size_t len, struct timeval *tv);
 #define MQTT_CMD_PINGRESP 13
 #define MQTT_CMD_DISCONNECT 14
 
-#define MQTT_QOS(qos) ((qos) << 1)
-#define MQTT_GET_QOS(flags) (((flags) &0x6) >> 1)
-#define MQTT_SET_QOS(flags, qos) (flags) = ((flags) & ~0x6) | ((qos) << 1)
-
 struct mg_mqtt_opts {
   struct mg_str user;          // Username, can be empty
   struct mg_str pass;          // Password, can be empty
diff --git a/src/event.h b/src/event.h
index 566fd53f..ddb136ee 100644
--- a/src/event.h
+++ b/src/event.h
@@ -8,6 +8,7 @@ void mg_error(struct mg_connection *c, const char *fmt, ...);
 
 enum {
   MG_EV_ERROR,       // Error                        char *error_message
+  MG_EV_OPEN,        // Connection created           NULL
   MG_EV_POLL,        // mg_mgr_poll iteration        unsigned long *millis
   MG_EV_RESOLVE,     // Host name is resolved        NULL
   MG_EV_CONNECT,     // Connection established       NULL
diff --git a/src/mqtt.c b/src/mqtt.c
index 064addc9..8f99b8ed 100644
--- a/src/mqtt.c
+++ b/src/mqtt.c
@@ -11,8 +11,6 @@
 #define MQTT_WILL_RETAIN 0x20
 #define MQTT_HAS_PASSWORD 0x40
 #define MQTT_HAS_USER_NAME 0x80
-#define MQTT_GET_WILL_QOS(flags) (((flags) &0x18) >> 3)
-#define MQTT_SET_WILL_QOS(flags, qos) (flags) = ((flags) & ~0x18) | ((qos) << 3)
 
 enum { MQTT_OK, MQTT_INCOMPLETE, MQTT_MALFORMED };
 
@@ -34,34 +32,43 @@ static void mg_send_u16(struct mg_connection *c, uint16_t value) {
 }
 
 void mg_mqtt_login(struct mg_connection *c, struct mg_mqtt_opts *opts) {
+  char rnd[9], client_id[16];
+  struct mg_str cid = opts->client_id;
   uint32_t total_len = 7 + 1 + 2 + 2;
-  uint16_t flags = (uint16_t) (((uint16_t) opts->qos & 3) << 3);
+  uint8_t connflag = (uint8_t) ((opts->qos & 3) << 1);
+
+  if (cid.len == 0) {
+    mg_random(rnd, sizeof(rnd));
+    mg_base64_encode((unsigned char *) rnd, sizeof(rnd), client_id);
+    client_id[sizeof(client_id) - 1] = '\0';
+    cid = mg_str(client_id);
+  }
 
   if (opts->user.len > 0) {
     total_len += 2 + (uint32_t) opts->user.len;
-    flags |= MQTT_HAS_USER_NAME;
+    connflag |= MQTT_HAS_USER_NAME;
   }
   if (opts->pass.len > 0) {
     total_len += 2 + (uint32_t) opts->pass.len;
-    flags |= MQTT_HAS_PASSWORD;
+    connflag |= MQTT_HAS_PASSWORD;
   }
   if (opts->will_topic.len > 0 && opts->will_message.len > 0) {
     total_len +=
         4 + (uint32_t) opts->will_topic.len + (uint32_t) opts->will_message.len;
-    flags |= MQTT_HAS_WILL;
+    connflag |= MQTT_HAS_WILL;
   }
-  if (opts->clean || opts->client_id.len == 0) flags |= MQTT_CLEAN_SESSION;
-  if (opts->will_retain) flags |= MQTT_WILL_RETAIN;
-  total_len += (uint32_t) opts->client_id.len;
+  if (opts->clean || cid.len == 0) connflag |= MQTT_CLEAN_SESSION;
+  if (opts->will_retain) connflag |= MQTT_WILL_RETAIN;
+  total_len += (uint32_t) cid.len;
 
   mg_mqtt_send_header(c, MQTT_CMD_CONNECT, 0, total_len);
   mg_send(c, "\00\04MQTT\04", 7);
-  mg_send(c, &flags, 1);
+  mg_send(c, &connflag, sizeof(connflag));
   // keepalive == 0 means "do not disconnect us!"
   mg_send_u16(c, mg_htons((uint16_t) opts->keepalive));
-  mg_send_u16(c, mg_htons((uint16_t) opts->client_id.len));
-  mg_send(c, opts->client_id.ptr, opts->client_id.len);
-  if (flags & MQTT_HAS_WILL) {
+  mg_send_u16(c, mg_htons((uint16_t) cid.len));
+  mg_send(c, cid.ptr, cid.len);
+  if (connflag & MQTT_HAS_WILL) {
     mg_send_u16(c, mg_htons((uint16_t) opts->will_topic.len));
     mg_send(c, opts->will_topic.ptr, opts->will_topic.len);
     mg_send_u16(c, mg_htons((uint16_t) opts->will_message.len));
@@ -83,11 +90,11 @@ void mg_mqtt_pub(struct mg_connection *c, struct mg_str *topic,
   uint32_t total_len = 2 + (uint32_t) topic->len + (uint32_t) data->len;
   LOG(LL_DEBUG, ("%lu [%.*s] -> [%.*s]", c->id, (int) topic->len,
                  (char *) topic->ptr, (int) data->len, (char *) data->ptr));
-  if (MQTT_GET_QOS(flags) > 0) total_len += 2;
+  if (qos > 0) total_len += 2;
   mg_mqtt_send_header(c, MQTT_CMD_PUBLISH, flags, total_len);
   mg_send_u16(c, mg_htons((uint16_t) topic->len));
   mg_send(c, topic->ptr, topic->len);
-  if (MQTT_GET_QOS(flags) > 0) {
+  if (qos > 0) {
     static uint16_t s_id;
     if (++s_id == 0) s_id++;
     mg_send_u16(c, mg_htons(s_id));
@@ -99,8 +106,7 @@ void mg_mqtt_sub(struct mg_connection *c, struct mg_str *topic, int qos) {
   static uint16_t s_id;
   uint8_t qos_ = qos & 3;
   uint32_t total_len = 2 + (uint32_t) topic->len + 2 + 1;
-  mg_mqtt_send_header(c, MQTT_CMD_SUBSCRIBE, (uint8_t) MQTT_QOS(qos_),
-                      total_len);
+  mg_mqtt_send_header(c, MQTT_CMD_SUBSCRIBE, 2, total_len);
   if (++s_id == 0) ++s_id;
   mg_send_u16(c, mg_htons(s_id));
   mg_send_u16(c, mg_htons((uint16_t) topic->len));
diff --git a/src/mqtt.h b/src/mqtt.h
index a9b3c3ac..5fb98c14 100644
--- a/src/mqtt.h
+++ b/src/mqtt.h
@@ -18,10 +18,6 @@
 #define MQTT_CMD_PINGRESP 13
 #define MQTT_CMD_DISCONNECT 14
 
-#define MQTT_QOS(qos) ((qos) << 1)
-#define MQTT_GET_QOS(flags) (((flags) &0x6) >> 1)
-#define MQTT_SET_QOS(flags, qos) (flags) = ((flags) & ~0x6) | ((qos) << 1)
-
 struct mg_mqtt_opts {
   struct mg_str user;          // Username, can be empty
   struct mg_str pass;          // Password, can be empty
diff --git a/src/sock.c b/src/sock.c
index c56a478f..2552799a 100644
--- a/src/sock.c
+++ b/src/sock.c
@@ -369,6 +369,7 @@ struct mg_connection *mg_connect(struct mg_mgr *mgr, const char *url,
     c->fn = fn;
     c->fn_data = fn_data;
     LOG(LL_DEBUG, ("%lu -> %s", c->id, url));
+    mg_call(c, MG_EV_OPEN, NULL);
     mg_resolve(c, &host, mgr->dnstimeout);
   }
   return c;
@@ -409,6 +410,7 @@ static void accept_conn(struct mg_mgr *mgr, struct mg_connection *lsn) {
     c->pfn_data = lsn->pfn_data;
     c->fn = lsn->fn;
     c->fn_data = lsn->fn_data;
+    mg_call(c, MG_EV_OPEN, NULL);
     mg_call(c, MG_EV_ACCEPT, NULL);
   }
 }
@@ -469,6 +471,7 @@ struct mg_connection *mg_mkpipe(struct mg_mgr *mgr, mg_event_handler_t fn,
     c->pfn_data = (void *) (size_t) sp[0];
     c->fn = fn;
     c->fn_data = fn_data;
+    mg_call(c, MG_EV_OPEN, NULL);
     LIST_ADD_HEAD(struct mg_connection, &mgr->conns, c);
   }
   return c;
@@ -493,7 +496,8 @@ struct mg_connection *mg_listen(struct mg_mgr *mgr, const char *url,
     LIST_ADD_HEAD(struct mg_connection, &mgr->conns, c);
     c->fn = fn;
     c->fn_data = fn_data;
-    LOG(LL_INFO,
+    mg_call(c, MG_EV_OPEN, NULL);
+    LOG(LL_DEBUG,
         ("%lu accepting on %s (port %u)", c->id, url, mg_ntohs(c->peer.port)));
   }
   return c;