diff --git a/include/kernel.h b/include/kernel.h
index 59fa082..0b48deb 100644
--- a/include/kernel.h
+++ b/include/kernel.h
@@ -1755,7 +1755,7 @@
  * @retval 0 on success
  * @retval -ENOMEM if there isn't sufficient RAM in the caller's resource pool
  */
-__syscall int k_queue_alloc_append(struct k_queue *queue, void *data);
+__syscall s32_t k_queue_alloc_append(struct k_queue *queue, void *data);
 
 /**
  * @brief Prepend an element to a queue.
@@ -1788,7 +1788,7 @@
  * @retval 0 on success
  * @retval -ENOMEM if there isn't sufficient RAM in the caller's resource pool
  */
-__syscall int k_queue_alloc_prepend(struct k_queue *queue, void *data);
+__syscall s32_t k_queue_alloc_prepend(struct k_queue *queue, void *data);
 
 /**
  * @brief Inserts an element to a queue.
diff --git a/kernel/queue.c b/kernel/queue.c
index 0bfd19a..2563496 100644
--- a/kernel/queue.c
+++ b/kernel/queue.c
@@ -34,7 +34,7 @@
 {
 	void *ret;
 
-	if (node && sys_sfnode_flags_get(node)) {
+	if ((node != NULL) && (sys_sfnode_flags_get(node) != (u8_t)0)) {
 		/* If the flag is set, then the enqueue operation for this item
 		 * did a behind-the scenes memory allocation of an alloc_node
 		 * struct, which is what got put in the queue. Free it and pass
@@ -121,7 +121,7 @@
 
 void _impl_k_queue_cancel_wait(struct k_queue *queue)
 {
-	unsigned int key = irq_lock();
+	u32_t key = irq_lock();
 #if !defined(CONFIG_POLL)
 	struct k_thread *first_pending_thread;
 
@@ -142,10 +142,10 @@
 			       struct k_queue *);
 #endif
 
-static int queue_insert(struct k_queue *queue, void *prev, void *data,
-			bool alloc)
+static s32_t queue_insert(struct k_queue *queue, void *prev, void *data,
+			  bool alloc)
 {
-	unsigned int key = irq_lock();
+	u32_t key = irq_lock();
 #if !defined(CONFIG_POLL)
 	struct k_thread *first_pending_thread;
 
@@ -198,7 +198,7 @@
 	(void)queue_insert(queue, NULL, data, false);
 }
 
-int _impl_k_queue_alloc_append(struct k_queue *queue, void *data)
+s32_t _impl_k_queue_alloc_append(struct k_queue *queue, void *data)
 {
 	return queue_insert(queue, sys_sflist_peek_tail(&queue->data_q), data,
 			    true);
@@ -214,7 +214,7 @@
 }
 #endif
 
-int _impl_k_queue_alloc_prepend(struct k_queue *queue, void *data)
+s32_t _impl_k_queue_alloc_prepend(struct k_queue *queue, void *data)
 {
 	return queue_insert(queue, NULL, data, true);
 }
@@ -343,7 +343,7 @@
 #else
 	int ret = _pend_current_thread(key, &queue->wait_q, timeout);
 
-	return ret ? NULL : _current->base.swap_data;
+	return (ret != 0) ? NULL : _current->base.swap_data;
 #endif /* CONFIG_POLL */
 }