diff --git a/include/kernel.h b/include/kernel.h
index ad8d76d1a4f..652c3c31788 100644
--- a/include/kernel.h
+++ b/include/kernel.h
@@ -1602,6 +1602,8 @@ extern void k_msgq_init(struct k_msgq *q, char *buffer,
  *
  * This routine sends a message to message queue @a q.
  *
+ * @note Can be called by ISRs.
+ *
  * @param q Address of the message queue.
  * @param data Pointer to the message.
  * @param timeout Waiting period to add the message (in milliseconds),
@@ -1619,6 +1621,8 @@ extern int k_msgq_put(struct k_msgq *q, void *data, int32_t timeout);
  * This routine receives a message from message queue @a q in a "first in,
  * first out" manner.
  *
+ * @note Can be called by ISRs.
+ *
  * @param q Address of the message queue.
  * @param data Address of area to hold the received message.
  * @param timeout Waiting period to receive the message (in milliseconds),
diff --git a/kernel/unified/msg_q.c b/kernel/unified/msg_q.c
index 7536872c38b..374a8faaecd 100644
--- a/kernel/unified/msg_q.c
+++ b/kernel/unified/msg_q.c
@@ -72,6 +72,8 @@ void k_msgq_init(struct k_msgq *q, char *buffer,
 
 int k_msgq_put(struct k_msgq *q, void *data, int32_t timeout)
 {
+	__ASSERT(!_is_in_isr() || timeout == K_NO_WAIT, "");
+
 	unsigned int key = irq_lock();
 	struct k_thread *pending_thread;
 	int result;
@@ -86,7 +88,7 @@ int k_msgq_put(struct k_msgq *q, void *data, int32_t timeout)
 			_set_thread_return_value(pending_thread, 0);
 			_abort_thread_timeout(pending_thread);
 			_ready_thread(pending_thread);
-			if (_must_switch_threads()) {
+			if (!_is_in_isr() && _must_switch_threads()) {
 				_Swap(key);
 				return 0;
 			}
@@ -117,6 +119,8 @@ int k_msgq_put(struct k_msgq *q, void *data, int32_t timeout)
 
 int k_msgq_get(struct k_msgq *q, void *data, int32_t timeout)
 {
+	__ASSERT(!_is_in_isr() || timeout == K_NO_WAIT, "");
+
 	unsigned int key = irq_lock();
 	struct k_thread *pending_thread;
 	int result;
@@ -146,7 +150,7 @@ int k_msgq_get(struct k_msgq *q, void *data, int32_t timeout)
 			_set_thread_return_value(pending_thread, 0);
 			_abort_thread_timeout(pending_thread);
 			_ready_thread(pending_thread);
-			if (_must_switch_threads()) {
+			if (!_is_in_isr() && _must_switch_threads()) {
 				_Swap(key);
 				return 0;
 			}