diff --git a/mongoose.c b/mongoose.c
index 2801a185e24..0e6e37c0f43 100644
--- a/mongoose.c
+++ b/mongoose.c
@@ -8122,6 +8122,7 @@ struct mg_tcpip_driver mg_tcpip_driver_w5500 = {w5500_init, w5500_tx, w5500_rx,
 #define MIP_TCP_ACK_MS 150    // Timeout for ACKing
 #define MIP_TCP_ARP_MS 100    // Timeout for ARP response
 #define MIP_TCP_SYN_MS 15000  // Timeout for connection establishment
+#define MIP_TCP_FIN_MS 100    // Timeout for closing connection
 
 struct connstate {
   uint32_t seq, ack;           // TCP seq/ack counters
@@ -8132,6 +8133,8 @@ struct connstate {
 #define MIP_TTYPE_ACK 1        // Peer sent us data, we have to ack it soon
 #define MIP_TTYPE_ARP 2        // ARP resolve sent, waiting for response
 #define MIP_TTYPE_SYN 3        // SYN sent, waiting for response
+#define MIP_TTYPE_FIN 4        // FIN sent, waiting until terminating the connection
+#define MIP_TTYPE_CLOSED 5     // Connection is closed
   uint8_t tmiss;               // Number of keep-alive misses
   struct mg_iobuf raw;         // For TLS only. Incoming raw data
 };
@@ -8271,6 +8274,7 @@ static void settmout(struct mg_connection *c, uint8_t type) {
   unsigned n = type == MIP_TTYPE_ACK   ? MIP_TCP_ACK_MS
                : type == MIP_TTYPE_ARP ? MIP_TCP_ARP_MS
                : type == MIP_TTYPE_SYN ? MIP_TCP_SYN_MS
+               : type == MIP_TTYPE_FIN ? MIP_TCP_FIN_MS
                                        : MIP_TCP_KEEPALIVE_MS;
   s->timer = ifp->now + n;
   s->ttype = type;
@@ -8694,8 +8698,15 @@ static void read_conn(struct mg_connection *c, struct pkt *pkt) {
   struct mg_iobuf *io = c->is_tls ? &s->raw : &c->recv;
   uint32_t seq = mg_ntohl(pkt->tcp->seq);
   s->raw.align = c->recv.align;
+  uint32_t rem_ip;
+  memcpy(&rem_ip, c->rem.ip, sizeof(uint32_t));
   if (pkt->tcp->flags & TH_FIN) {
     s->ack = mg_htonl(pkt->tcp->seq) + 1, s->seq = mg_htonl(pkt->tcp->ack);
+    if (c->is_closing)
+    // We initiated FIN so when we receive FIN, we will have to ACK it
+      tx_tcp((struct mg_tcpip_if *) c->mgr->priv, s->mac, rem_ip, TH_ACK,
+            c->loc.port, c->rem.port, mg_htonl(s->seq), mg_htonl(s->ack), "",
+            0);
     c->is_closing = 1;
   } else if (pkt->pay.len == 0) {
     // TODO(cpq): handle this peer's ACK
@@ -8704,8 +8715,6 @@ static void read_conn(struct mg_connection *c, struct pkt *pkt) {
     if (s->ack == ack) {
       MG_VERBOSE(("ignoring duplicate pkt"));
     } else {
-      uint32_t rem_ip;
-      memcpy(&rem_ip, c->rem.ip, sizeof(uint32_t));
       MG_VERBOSE(("SEQ != ACK: %x %x %x", seq, s->ack, ack));
       tx_tcp((struct mg_tcpip_if *) c->mgr->priv, s->mac, rem_ip, TH_ACK,
              c->loc.port, c->rem.port, mg_htonl(s->seq), mg_htonl(s->ack), "",
@@ -8973,6 +8982,9 @@ static void mg_tcpip_poll(struct mg_tcpip_if *ifp, uint64_t uptime_ms) {
         mg_error(c, "ARP timeout");
       } else if (s->ttype == MIP_TTYPE_SYN) {
         mg_error(c, "Connection timeout");
+      } else if (s->ttype == MIP_TTYPE_FIN) {
+        s->ttype = MIP_TTYPE_CLOSED;
+        continue;
       } else {
         if (s->tmiss++ > 2) {
           mg_error(c, "keepalive");
@@ -8982,6 +8994,7 @@ static void mg_tcpip_poll(struct mg_tcpip_if *ifp, uint64_t uptime_ms) {
                  mg_htonl(s->seq - 1), mg_htonl(s->ack), "", 0);
         }
       }
+
       settmout(c, MIP_TTYPE_KEEPALIVE);
     }
   }
@@ -9113,10 +9126,16 @@ static void close_conn(struct mg_connection *c) {
   mg_iobuf_free(&s->raw);  // For TLS connections, release raw data
   if (c->is_udp == false && c->is_listening == false &&
       c->is_connecting == false) {  // For TCP conns,
-    struct mg_tcpip_if *ifp =
+    if (s->ttype != MIP_TTYPE_FIN && s->ttype != MIP_TTYPE_CLOSED) {
+      struct mg_tcpip_if *ifp =
         (struct mg_tcpip_if *) c->mgr->priv;  // send TCP FIN
-    tx_tcp(ifp, s->mac, rem_ip, TH_FIN | TH_ACK, c->loc.port, c->rem.port,
-           mg_htonl(s->seq), mg_htonl(s->ack), NULL, 0);
+      tx_tcp(ifp, s->mac, rem_ip, TH_FIN | TH_ACK, c->loc.port, c->rem.port,
+            mg_htonl(s->seq), mg_htonl(s->ack), NULL, 0);
+      settmout(c, MIP_TTYPE_FIN);
+    } else if (s->ttype == MIP_TTYPE_CLOSED) {
+      mg_close_conn(c);
+    }
+    return;
   }
   mg_close_conn(c);
 }
diff --git a/src/tcpip/tcpip.c b/src/tcpip/tcpip.c
index a0078f87b76..cebd1ff7fb7 100644
--- a/src/tcpip/tcpip.c
+++ b/src/tcpip/tcpip.c
@@ -12,6 +12,7 @@
 #define MIP_TCP_ACK_MS 150    // Timeout for ACKing
 #define MIP_TCP_ARP_MS 100    // Timeout for ARP response
 #define MIP_TCP_SYN_MS 15000  // Timeout for connection establishment
+#define MIP_TCP_FIN_MS 100    // Timeout for closing connection
 
 struct connstate {
   uint32_t seq, ack;           // TCP seq/ack counters
@@ -22,6 +23,8 @@ struct connstate {
 #define MIP_TTYPE_ACK 1        // Peer sent us data, we have to ack it soon
 #define MIP_TTYPE_ARP 2        // ARP resolve sent, waiting for response
 #define MIP_TTYPE_SYN 3        // SYN sent, waiting for response
+#define MIP_TTYPE_FIN 4        // FIN sent, waiting until terminating the connection
+#define MIP_TTYPE_CLOSED 5     // Connection is closed
   uint8_t tmiss;               // Number of keep-alive misses
   struct mg_iobuf raw;         // For TLS only. Incoming raw data
 };
@@ -161,6 +164,7 @@ static void settmout(struct mg_connection *c, uint8_t type) {
   unsigned n = type == MIP_TTYPE_ACK   ? MIP_TCP_ACK_MS
                : type == MIP_TTYPE_ARP ? MIP_TCP_ARP_MS
                : type == MIP_TTYPE_SYN ? MIP_TCP_SYN_MS
+               : type == MIP_TTYPE_FIN ? MIP_TCP_FIN_MS
                                        : MIP_TCP_KEEPALIVE_MS;
   s->timer = ifp->now + n;
   s->ttype = type;
@@ -584,8 +588,15 @@ static void read_conn(struct mg_connection *c, struct pkt *pkt) {
   struct mg_iobuf *io = c->is_tls ? &s->raw : &c->recv;
   uint32_t seq = mg_ntohl(pkt->tcp->seq);
   s->raw.align = c->recv.align;
+  uint32_t rem_ip;
+  memcpy(&rem_ip, c->rem.ip, sizeof(uint32_t));
   if (pkt->tcp->flags & TH_FIN) {
     s->ack = mg_htonl(pkt->tcp->seq) + 1, s->seq = mg_htonl(pkt->tcp->ack);
+    if (c->is_closing)
+    // We initiated FIN so when we receive FIN, we will have to ACK it
+      tx_tcp((struct mg_tcpip_if *) c->mgr->priv, s->mac, rem_ip, TH_ACK,
+            c->loc.port, c->rem.port, mg_htonl(s->seq), mg_htonl(s->ack), "",
+            0);
     c->is_closing = 1;
   } else if (pkt->pay.len == 0) {
     // TODO(cpq): handle this peer's ACK
@@ -594,8 +605,6 @@ static void read_conn(struct mg_connection *c, struct pkt *pkt) {
     if (s->ack == ack) {
       MG_VERBOSE(("ignoring duplicate pkt"));
     } else {
-      uint32_t rem_ip;
-      memcpy(&rem_ip, c->rem.ip, sizeof(uint32_t));
       MG_VERBOSE(("SEQ != ACK: %x %x %x", seq, s->ack, ack));
       tx_tcp((struct mg_tcpip_if *) c->mgr->priv, s->mac, rem_ip, TH_ACK,
              c->loc.port, c->rem.port, mg_htonl(s->seq), mg_htonl(s->ack), "",
@@ -863,6 +872,9 @@ static void mg_tcpip_poll(struct mg_tcpip_if *ifp, uint64_t uptime_ms) {
         mg_error(c, "ARP timeout");
       } else if (s->ttype == MIP_TTYPE_SYN) {
         mg_error(c, "Connection timeout");
+      } else if (s->ttype == MIP_TTYPE_FIN) {
+        s->ttype = MIP_TTYPE_CLOSED;
+        continue;
       } else {
         if (s->tmiss++ > 2) {
           mg_error(c, "keepalive");
@@ -872,6 +884,7 @@ static void mg_tcpip_poll(struct mg_tcpip_if *ifp, uint64_t uptime_ms) {
                  mg_htonl(s->seq - 1), mg_htonl(s->ack), "", 0);
         }
       }
+
       settmout(c, MIP_TTYPE_KEEPALIVE);
     }
   }
@@ -1003,10 +1016,16 @@ static void close_conn(struct mg_connection *c) {
   mg_iobuf_free(&s->raw);  // For TLS connections, release raw data
   if (c->is_udp == false && c->is_listening == false &&
       c->is_connecting == false) {  // For TCP conns,
-    struct mg_tcpip_if *ifp =
+    if (s->ttype != MIP_TTYPE_FIN && s->ttype != MIP_TTYPE_CLOSED) {
+      struct mg_tcpip_if *ifp =
         (struct mg_tcpip_if *) c->mgr->priv;  // send TCP FIN
-    tx_tcp(ifp, s->mac, rem_ip, TH_FIN | TH_ACK, c->loc.port, c->rem.port,
-           mg_htonl(s->seq), mg_htonl(s->ack), NULL, 0);
+      tx_tcp(ifp, s->mac, rem_ip, TH_FIN | TH_ACK, c->loc.port, c->rem.port,
+            mg_htonl(s->seq), mg_htonl(s->ack), NULL, 0);
+      settmout(c, MIP_TTYPE_FIN);
+    } else if (s->ttype == MIP_TTYPE_CLOSED) {
+      mg_close_conn(c);
+    }
+    return;
   }
   mg_close_conn(c);
 }
diff --git a/test/mip_tap_test.c b/test/mip_tap_test.c
index 97333c4dc19..c96007375b7 100644
--- a/test/mip_tap_test.c
+++ b/test/mip_tap_test.c
@@ -103,6 +103,7 @@ char *fetch(struct mg_mgr *mgr, const char *url, const char *fn_data) {
   }
   if (mgr->conns != 0) {
     conn->is_closing = 1;
+    usleep(150000);
     mg_mgr_poll(mgr, 0);
   }
   mg_mgr_poll(mgr, 0);
@@ -175,9 +176,9 @@ static void test_http_fetch(void) {
 
 #if MG_USING_DHCP == 1
 #else
-  mif.ip = 0x0220a8c0;    // 192.168.32.2 // Triggering a network failure
-  mif.mask = 0x00ffffff;  // 255.255.255.0
-  mif.gw = 0x0120a8c0;    // 192.168.32.1
+  mif.ip = mg_htonl(MG_U32(192, 168, 32, 2));    // Triggering a network failure
+  mif.mask = mg_htonl(MG_U32(255, 255, 255, 0))
+  mif.gw = mg_htonl(MG_U32(192, 168, 0, 1));
 #endif
 
   sscanf(mac, "%hhx:%hhx:%hhx:%hhx:%hhx:%hhx", &mif.mac[0], &mif.mac[1],