diff --git a/lib/src/phy/rf/rf_zmq_imp_rx.c b/lib/src/phy/rf/rf_zmq_imp_rx.c
index bb84f7506..4d0678c61 100644
--- a/lib/src/phy/rf/rf_zmq_imp_rx.c
+++ b/lib/src/phy/rf/rf_zmq_imp_rx.c
@@ -17,11 +17,20 @@
 #include <string.h>
 #include <zmq.h>
 
+bool is_rx_running(rf_zmq_rx_t* q)
+{
+  bool running = false;
+  pthread_mutex_lock(&q->mutex);
+  running = q->running;
+  pthread_mutex_unlock(&q->mutex);
+  return running;
+}
+
 static void* rf_zmq_async_rx_thread(void* h)
 {
   rf_zmq_rx_t* q = (rf_zmq_rx_t*)h;
 
-  while (q->sock && q->running) {
+  while (q->sock && is_rx_running(q)) {
     int     nbytes = 0;
     int     n      = SRSRAN_ERROR;
     uint8_t dummy  = 0xFF;
@@ -30,7 +39,7 @@ static void* rf_zmq_async_rx_thread(void* h)
 
     // Send request if socket type is REQUEST
     if (q->socket_type == ZMQ_REQ) {
-      while (n < 0 && q->running) {
+      while (n < 0 && is_rx_running(q)) {
         rf_zmq_info(q->id, " - tx'ing rx request\n");
         n = zmq_send(q->sock, &dummy, sizeof(dummy), 0);
         if (n < 0) {
@@ -44,7 +53,7 @@ static void* rf_zmq_async_rx_thread(void* h)
     }
 
     // Receive baseband
-    for (n = (n < 0) ? 0 : -1; n < 0 && q->running;) {
+    for (n = (n < 0) ? 0 : -1; n < 0 && is_rx_running(q);) {
       n = zmq_recv(q->sock, q->temp_buffer, ZMQ_MAX_BUFFER_SIZE, 0);
       if (n == -1) {
         if (rf_zmq_handle_error(q->id, "asynchronous rx baseband receive")) {
@@ -68,7 +77,7 @@ static void* rf_zmq_async_rx_thread(void* h)
       n = -1;
 
       // Try to write in ring buffer
-      while (n < 0 && q->running) {
+      while (n < 0 && is_rx_running(q)) {
         n = srsran_ringbuffer_write_timed(&q->ringbuffer, q->temp_buffer, nbytes, q->trx_timeout_ms);
         if (n == SRSRAN_ERROR_TIMEOUT && q->log_trx_timeout) {
           fprintf(stderr, "Error: timeout writing samples to ringbuffer after %dms\n", q->trx_timeout_ms);
@@ -253,13 +262,18 @@ bool rf_zmq_rx_match_freq(rf_zmq_rx_t* q, uint32_t freq_hz)
 void rf_zmq_rx_close(rf_zmq_rx_t* q)
 {
   rf_zmq_info(q->id, "Closing ...\n");
+
+  pthread_mutex_lock(&q->mutex);
   q->running = false;
+  pthread_mutex_unlock(&q->mutex);
 
   if (q->thread) {
     pthread_join(q->thread, NULL);
     pthread_detach(q->thread);
   }
 
+  pthread_mutex_destroy(&q->mutex);
+
   srsran_ringbuffer_free(&q->ringbuffer);
 
   if (q->temp_buffer) {
diff --git a/lib/src/phy/rf/rf_zmq_imp_tx.c b/lib/src/phy/rf/rf_zmq_imp_tx.c
index 81417b53c..078a5b92f 100644
--- a/lib/src/phy/rf/rf_zmq_imp_tx.c
+++ b/lib/src/phy/rf/rf_zmq_imp_tx.c
@@ -223,7 +223,11 @@ bool rf_zmq_tx_match_freq(rf_zmq_tx_t* q, uint32_t freq_hz)
 
 void rf_zmq_tx_close(rf_zmq_tx_t* q)
 {
+  pthread_mutex_lock(&q->mutex);
   q->running = false;
+  pthread_mutex_unlock(&q->mutex);
+
+  pthread_mutex_destroy(&q->mutex);
 
   if (q->zeros) {
     free(q->zeros);
diff --git a/lib/src/phy/utils/ringbuffer.c b/lib/src/phy/utils/ringbuffer.c
index 53359c356..cdd6ee7f7 100644
--- a/lib/src/phy/utils/ringbuffer.c
+++ b/lib/src/phy/utils/ringbuffer.c
@@ -78,7 +78,11 @@ int srsran_ringbuffer_resize(srsran_ringbuffer_t* q, int capacity)
 
 int srsran_ringbuffer_status(srsran_ringbuffer_t* q)
 {
-  return q->count;
+  int status = 0;
+  pthread_mutex_lock(&q->mutex);
+  status = q->count;
+  pthread_mutex_unlock(&q->mutex);
+  return status;
 }
 
 int srsran_ringbuffer_space(srsran_ringbuffer_t* q)