diff --git a/core/lib/include/priority_queue.h b/core/lib/include/priority_queue.h
index 3c58b75bb3..a33e545d73 100644
--- a/core/lib/include/priority_queue.h
+++ b/core/lib/include/priority_queue.h
@@ -32,7 +32,7 @@ extern "C" {
 typedef struct priority_queue_node {
     struct priority_queue_node *next;   /**< next queue node */
     uint32_t priority;                  /**< queue node priority */
-    unsigned int data;                  /**< queue node data */
+    uintptr_t data;                     /**< queue node data */
 } priority_queue_node_t;
 
 /**
diff --git a/core/lib/priority_queue.c b/core/lib/priority_queue.c
index c7f734cc7a..e02db44697 100644
--- a/core/lib/priority_queue.c
+++ b/core/lib/priority_queue.c
@@ -78,14 +78,14 @@ void priority_queue_print(priority_queue_t *root)
     printf("queue:\n");
 
     for (priority_queue_node_t *node = root->first; node; node = node->next) {
-        printf("Data: %u Priority: %lu\n", node->data,
-               (unsigned long)node->priority);
+        printf("Data: %" PRIuPTR " Priority: %" PRIu32 "\n", node->data,
+               node->priority);
     }
 }
 
 void priority_queue_print_node(priority_queue_node_t *node)
 {
-    printf("Data: %u Priority: %lu Next: %u\n", (unsigned int)node->data,
-           (unsigned long)node->priority, (unsigned int)node->next);
+    printf("Data: %" PRIuPTR " Priority: %" PRIu32 " Next: %p\n", node->data,
+           node->priority, (void *)node->next);
 }
 #endif
diff --git a/core/mbox.c b/core/mbox.c
index dce9140cf6..f636804a3c 100644
--- a/core/mbox.c
+++ b/core/mbox.c
@@ -64,8 +64,8 @@ int _mbox_put(mbox_t *mbox, msg_t *msg, int blocking)
     list_node_t *next = list_remove_head(&mbox->readers);
 
     if (next) {
-        DEBUG("mbox: Thread %" PRIkernel_pid " mbox 0x%08x: _tryput(): "
-              "there's a waiter.\n", thread_getpid(), (unsigned)mbox);
+        DEBUG("mbox: Thread %" PRIkernel_pid " mbox 0x%08" PRIxPTR ": _tryput(): "
+              "there's a waiter.\n", thread_getpid(), (uintptr_t)mbox);
         thread_t *thread =
             container_of((clist_node_t *)next, thread_t, rq_entry);
         *(msg_t *)thread->wait_data = *msg;
@@ -84,8 +84,8 @@ int _mbox_put(mbox_t *mbox, msg_t *msg, int blocking)
             }
         }
 
-        DEBUG("mbox: Thread %" PRIkernel_pid " mbox 0x%08x: _tryput(): "
-              "queued message.\n", thread_getpid(), (unsigned)mbox);
+        DEBUG("mbox: Thread %" PRIkernel_pid " mbox 0x%08" PRIxPTR ": _tryput(): "
+              "queued message.\n", thread_getpid(), (uintptr_t)mbox);
         msg->sender_pid = thread_getpid();
         /* copy msg into queue */
         mbox->msg_array[cib_put_unsafe(&mbox->cib)] = *msg;
@@ -99,8 +99,8 @@ int _mbox_get(mbox_t *mbox, msg_t *msg, int blocking)
     unsigned irqstate = irq_disable();
 
     if (cib_avail(&mbox->cib)) {
-        DEBUG("mbox: Thread %" PRIkernel_pid " mbox 0x%08x: _tryget(): "
-              "got queued message.\n", thread_getpid(), (unsigned)mbox);
+        DEBUG("mbox: Thread %" PRIkernel_pid " mbox 0x%08" PRIxPTR ": _tryget(): "
+              "got queued message.\n", thread_getpid(), (uintptr_t)mbox);
         /* copy msg from queue */
         *msg = mbox->msg_array[cib_get_unsafe(&mbox->cib)];
         list_node_t *next = list_remove_head(&mbox->writers);
diff --git a/core/thread_flags.c b/core/thread_flags.c
index 1d4db08f10..be3c1bf44f 100644
--- a/core/thread_flags.c
+++ b/core/thread_flags.c
@@ -29,7 +29,7 @@ static inline int __attribute__((always_inline)) _thread_flags_wake(
     thread_t *thread)
 {
     unsigned wakeup;
-    thread_flags_t mask = (uint16_t)(unsigned)thread->wait_data;
+    thread_flags_t mask = (uint16_t)(uintptr_t)thread->wait_data;
 
     switch (thread->status) {
     case STATUS_FLAG_BLOCKED_ANY:
@@ -76,7 +76,7 @@ static void _thread_flags_wait(thread_flags_t mask, thread_t *thread,
         "_thread_flags_wait: me->flags=0x%08x me->mask=0x%08x. going blocked.\n",
         (unsigned)thread->flags, (unsigned)mask);
 
-    thread->wait_data = (void *)(unsigned)mask;
+    thread->wait_data = (void *)(uintptr_t)mask;
     sched_set_status(thread, threadstate);
     irq_restore(irqstate);
     thread_yield_higher();