diff --git a/sys/net/gnrc/transport_layer/tcp/gnrc_tcp.c b/sys/net/gnrc/transport_layer/tcp/gnrc_tcp.c
index 495cfd77ef..40a4586d17 100644
--- a/sys/net/gnrc/transport_layer/tcp/gnrc_tcp.c
+++ b/sys/net/gnrc/transport_layer/tcp/gnrc_tcp.c
@@ -100,12 +100,14 @@ static int _gnrc_tcp_open(gnrc_tcp_tcb_t *tcb, const gnrc_tcp_ep_t *remote,
     msg_t msg_queue[TCP_MSG_QUEUE_SIZE];
     mbox_t mbox = MBOX_INIT(msg_queue, TCP_MSG_QUEUE_SIZE);
     int ret = 0;
+    _gnrc_tcp_fsm_state_t state = 0;
 
     /* Lock the TCB for this function call */
     mutex_lock(&(tcb->function_lock));
 
     /* TCB is already connected: Return -EISCONN */
-    if (tcb->state != FSM_STATE_CLOSED) {
+    state = _gnrc_tcp_fsm_get_state(tcb);
+    if (state != FSM_STATE_CLOSED) {
         mutex_unlock(&(tcb->function_lock));
         TCP_DEBUG_ERROR("-EISCONN: TCB already connected.");
         TCP_DEBUG_LEAVE;
@@ -177,8 +179,9 @@ static int _gnrc_tcp_open(gnrc_tcp_tcb_t *tcb, const gnrc_tcp_ep_t *remote,
     }
 
     /* Wait until a connection was established or closed */
-    while (ret >= 0 && tcb->state != FSM_STATE_CLOSED && tcb->state != FSM_STATE_ESTABLISHED &&
-           tcb->state != FSM_STATE_CLOSE_WAIT) {
+    state = _gnrc_tcp_fsm_get_state(tcb);
+    while (ret >= 0 && state != FSM_STATE_CLOSED && state != FSM_STATE_ESTABLISHED &&
+           state != FSM_STATE_CLOSE_WAIT) {
         mbox_get(&mbox, &msg);
         switch (msg.type) {
             case MSG_TYPE_NOTIFY_USER:
@@ -187,7 +190,8 @@ static int _gnrc_tcp_open(gnrc_tcp_tcb_t *tcb, const gnrc_tcp_ep_t *remote,
                 /* Setup a timeout to be able to revert back to LISTEN state, in case the
                  * send SYN+ACK we received upon entering SYN_RCVD is never acknowledged
                  * by the peer. */
-                if ((tcb->state == FSM_STATE_SYN_RCVD) && (tcb->status & STATUS_PASSIVE)) {
+                state = _gnrc_tcp_fsm_get_state(tcb);
+                if ((state == FSM_STATE_SYN_RCVD) && (tcb->status & STATUS_PASSIVE)) {
                     _unsched_mbox(&tcb->event_misc);
                     _sched_connection_timeout(&tcb->event_misc, &mbox);
                 }
@@ -214,12 +218,13 @@ static int _gnrc_tcp_open(gnrc_tcp_tcb_t *tcb, const gnrc_tcp_ep_t *remote,
             default:
                 TCP_DEBUG_ERROR("Received unexpected message.");
         }
+        state = _gnrc_tcp_fsm_get_state(tcb);
     }
 
     /* Cleanup */
     _gnrc_tcp_fsm_set_mbox(tcb, NULL);
     _unsched_mbox(&tcb->event_misc);
-    if (tcb->state == FSM_STATE_CLOSED && ret == 0) {
+    if (state == FSM_STATE_CLOSED && ret == 0) {
         TCP_DEBUG_ERROR("-ECONNREFUSED: Connection refused by peer.");
         ret = -ECONNREFUSED;
     }
@@ -498,12 +503,14 @@ ssize_t gnrc_tcp_send(gnrc_tcp_tcb_t *tcb, const void *data, const size_t len,
     uint32_t probe_timeout_duration_ms = 0;
     ssize_t ret = 0;
     bool probing_mode = false;
+    _gnrc_tcp_fsm_state_t state = 0;
 
     /* Lock the TCB for this function call */
     mutex_lock(&(tcb->function_lock));
 
     /* Check if connection is in a valid state */
-    if (tcb->state != FSM_STATE_ESTABLISHED && tcb->state != FSM_STATE_CLOSE_WAIT) {
+    state = _gnrc_tcp_fsm_get_state(tcb);
+    if (state != FSM_STATE_ESTABLISHED && state != FSM_STATE_CLOSE_WAIT) {
         mutex_unlock(&(tcb->function_lock));
         TCP_DEBUG_ERROR("-ENOTCONN: TCB is not connected.");
         TCP_DEBUG_LEAVE;
@@ -523,8 +530,10 @@ ssize_t gnrc_tcp_send(gnrc_tcp_tcb_t *tcb, const void *data, const size_t len,
 
     /* Loop until something was sent and acked */
     while (ret == 0 || tcb->pkt_retransmit != NULL) {
+        state = _gnrc_tcp_fsm_get_state(tcb);
+
         /* Check if the connections state is closed. If so, a reset was received */
-        if (tcb->state == FSM_STATE_CLOSED) {
+        if (state == FSM_STATE_CLOSED) {
             TCP_DEBUG_ERROR("-ECONNRESET: Connection was reset by peer.");
             ret = -ECONNRESET;
             break;
@@ -621,13 +630,15 @@ ssize_t gnrc_tcp_recv(gnrc_tcp_tcb_t *tcb, void *data, const size_t max_len,
     mbox_t mbox = MBOX_INIT(msg_queue, TCP_MSG_QUEUE_SIZE);
     evtimer_mbox_event_t event_user_timeout;
     ssize_t ret = 0;
+    _gnrc_tcp_fsm_state_t state = 0;
 
     /* Lock the TCB for this function call */
     mutex_lock(&(tcb->function_lock));
 
     /* Check if connection is in a valid state */
-    if (tcb->state != FSM_STATE_ESTABLISHED && tcb->state != FSM_STATE_FIN_WAIT_1 &&
-        tcb->state != FSM_STATE_FIN_WAIT_2 && tcb->state != FSM_STATE_CLOSE_WAIT) {
+    state = _gnrc_tcp_fsm_get_state(tcb);
+    if (state != FSM_STATE_ESTABLISHED && state != FSM_STATE_FIN_WAIT_1 &&
+        state != FSM_STATE_FIN_WAIT_2 && state != FSM_STATE_CLOSE_WAIT) {
         mutex_unlock(&(tcb->function_lock));
         TCP_DEBUG_ERROR("-ENOTCONN: TCB is not connected.");
         TCP_DEBUG_LEAVE;
@@ -636,7 +647,7 @@ ssize_t gnrc_tcp_recv(gnrc_tcp_tcb_t *tcb, void *data, const size_t max_len,
 
     /* If FIN was received (CLOSE_WAIT), no further data can be received. */
     /* Copy received data into given buffer and return number of bytes. Can be zero. */
-    if (tcb->state == FSM_STATE_CLOSE_WAIT) {
+    if (state == FSM_STATE_CLOSE_WAIT) {
         ret = _gnrc_tcp_fsm(tcb, FSM_EVENT_CALL_RECV, NULL, data, max_len);
         mutex_unlock(&(tcb->function_lock));
         TCP_DEBUG_LEAVE;
@@ -669,7 +680,8 @@ ssize_t gnrc_tcp_recv(gnrc_tcp_tcb_t *tcb, void *data, const size_t max_len,
     /* Processing loop */
     while (ret == 0) {
         /* Check if the connections state is closed. If so, a reset was received */
-        if (tcb->state == FSM_STATE_CLOSED) {
+        state = _gnrc_tcp_fsm_get_state(tcb);
+        if (state == FSM_STATE_CLOSED) {
             TCP_DEBUG_ERROR("-ECONNRESET: Connection was reset by peer.");
             ret = -ECONNRESET;
             break;
@@ -679,7 +691,7 @@ ssize_t gnrc_tcp_recv(gnrc_tcp_tcb_t *tcb, void *data, const size_t max_len,
         ret = _gnrc_tcp_fsm(tcb, FSM_EVENT_CALL_RECV, NULL, data, max_len);
 
         /* If FIN was received (CLOSE_WAIT), no further data can be received. Leave event loop */
-        if (tcb->state == FSM_STATE_CLOSE_WAIT) {
+        if (state == FSM_STATE_CLOSE_WAIT) {
             break;
         }
 
@@ -728,12 +740,14 @@ void gnrc_tcp_close(gnrc_tcp_tcb_t *tcb)
     msg_t msg;
     msg_t msg_queue[TCP_MSG_QUEUE_SIZE];
     mbox_t mbox = MBOX_INIT(msg_queue, TCP_MSG_QUEUE_SIZE);
+    _gnrc_tcp_fsm_state_t state = 0;
 
     /* Lock the TCB for this function call */
     mutex_lock(&(tcb->function_lock));
 
     /* Return if connection is closed */
-    if (tcb->state == FSM_STATE_CLOSED) {
+    state = _gnrc_tcp_fsm_get_state(tcb);
+    if (state == FSM_STATE_CLOSED) {
         mutex_unlock(&(tcb->function_lock));
         TCP_DEBUG_LEAVE;
         return;
@@ -749,7 +763,8 @@ void gnrc_tcp_close(gnrc_tcp_tcb_t *tcb)
     _gnrc_tcp_fsm(tcb, FSM_EVENT_CALL_CLOSE, NULL, NULL, 0);
 
     /* Loop until the connection has been closed */
-    while (tcb->state != FSM_STATE_CLOSED) {
+    state = _gnrc_tcp_fsm_get_state(tcb);
+    while (state != FSM_STATE_CLOSED) {
         mbox_get(&mbox, &msg);
         switch (msg.type) {
             case MSG_TYPE_CONNECTION_TIMEOUT:
@@ -764,6 +779,7 @@ void gnrc_tcp_close(gnrc_tcp_tcb_t *tcb)
             default:
                 TCP_DEBUG_ERROR("Received unexpected message.");
         }
+        state = _gnrc_tcp_fsm_get_state(tcb);
     }
 
     /* Cleanup */
@@ -780,7 +796,7 @@ void gnrc_tcp_abort(gnrc_tcp_tcb_t *tcb)
 
     /* Lock the TCB for this function call */
     mutex_lock(&(tcb->function_lock));
-    if (tcb->state != FSM_STATE_CLOSED) {
+    if (_gnrc_tcp_fsm_get_state(tcb) != FSM_STATE_CLOSED) {
         /* Call FSM ABORT event */
         _gnrc_tcp_fsm(tcb, FSM_EVENT_CALL_ABORT, NULL, NULL, 0);
     }
diff --git a/sys/net/gnrc/transport_layer/tcp/gnrc_tcp_eventloop.c b/sys/net/gnrc/transport_layer/tcp/gnrc_tcp_eventloop.c
index 9ea4b58d6d..d05a3ea400 100644
--- a/sys/net/gnrc/transport_layer/tcp/gnrc_tcp_eventloop.c
+++ b/sys/net/gnrc/transport_layer/tcp/gnrc_tcp_eventloop.c
@@ -217,7 +217,8 @@ static int _receive(gnrc_pktsnip_t *pkt)
         if (ip->type == GNRC_NETTYPE_IPV6 && tcb->address_family == AF_INET6) {
             /* If SYN is set, a connection is listening on that port ... */
             ipv6_addr_t *tmp_addr = NULL;
-            if (syn && tcb->local_port == dst && tcb->state == FSM_STATE_LISTEN) {
+            _gnrc_tcp_fsm_state_t state = _gnrc_tcp_fsm_get_state(tcb);
+            if (syn && tcb->local_port == dst && state == FSM_STATE_LISTEN) {
                 /* ... and local addr is unspec or pre configured */
                 tmp_addr = &((ipv6_hdr_t *)ip->data)->dst;
                 if (ipv6_addr_equal((ipv6_addr_t *) tcb->local_addr, (ipv6_addr_t *) tmp_addr) ||
diff --git a/sys/net/gnrc/transport_layer/tcp/gnrc_tcp_fsm.c b/sys/net/gnrc/transport_layer/tcp/gnrc_tcp_fsm.c
index 7e311da9bc..04a03f990f 100644
--- a/sys/net/gnrc/transport_layer/tcp/gnrc_tcp_fsm.c
+++ b/sys/net/gnrc/transport_layer/tcp/gnrc_tcp_fsm.c
@@ -971,3 +971,13 @@ void _gnrc_tcp_fsm_set_mbox(gnrc_tcp_tcb_t *tcb, mbox_t *mbox)
     mutex_unlock(&(tcb->fsm_lock));
     TCP_DEBUG_LEAVE;
 }
+
+_gnrc_tcp_fsm_state_t _gnrc_tcp_fsm_get_state(gnrc_tcp_tcb_t *tcb)
+{
+    TCP_DEBUG_ENTER;
+    mutex_lock(&(tcb->fsm_lock));
+    _gnrc_tcp_fsm_state_t res = tcb->state;
+    mutex_unlock(&(tcb->fsm_lock));
+    TCP_DEBUG_LEAVE;
+    return res;
+}
diff --git a/sys/net/gnrc/transport_layer/tcp/include/gnrc_tcp_fsm.h b/sys/net/gnrc/transport_layer/tcp/include/gnrc_tcp_fsm.h
index 6260264af6..4f8f928677 100644
--- a/sys/net/gnrc/transport_layer/tcp/include/gnrc_tcp_fsm.h
+++ b/sys/net/gnrc/transport_layer/tcp/include/gnrc_tcp_fsm.h
@@ -88,6 +88,15 @@ int _gnrc_tcp_fsm(gnrc_tcp_tcb_t *tcb, _gnrc_tcp_fsm_event_t event,
  */
 void _gnrc_tcp_fsm_set_mbox(gnrc_tcp_tcb_t *tcb, mbox_t *mbox);
 
+/**
+ * @brief Get latest FSM state from given TCB.
+ *
+ * @param[in] tcb   TCB to get state from.
+ *
+ * @return   Current TCB state.
+ */
+_gnrc_tcp_fsm_state_t _gnrc_tcp_fsm_get_state(gnrc_tcp_tcb_t *tcb);
+
 #ifdef __cplusplus
 }
 #endif