Index: kernel/generic/src/ipc/kbox.c
===================================================================
--- kernel/generic/src/ipc/kbox.c	(revision fc0de8c33fadd1f6730eb0465b89c7afa861fe56)
+++ kernel/generic/src/ipc/kbox.c	(revision 1871118c75a2375392bbb2054288202965beca01)
@@ -90,5 +90,5 @@
 		LOG("Join kb.thread.");
 		thread_join(TASK->kb.thread);
-		thread_detach(TASK->kb.thread);
+		thread_put(TASK->kb.thread);
 		LOG("...join done.");
 		TASK->kb.thread = NULL;
@@ -136,6 +136,6 @@
 		/* Only detach kbox thread unless already terminating. */
 		if (TASK->kb.finished == false) {
-			/* Detach kbox thread so it gets freed from memory. */
-			thread_detach(TASK->kb.thread);
+			/* Release kbox thread so it gets freed from memory. */
+			thread_put(TASK->kb.thread);
 			TASK->kb.thread = NULL;
 		}
@@ -247,5 +247,5 @@
 		}
 
-		task->kb.thread = kb_thread;
+		task->kb.thread = thread_ref(kb_thread);
 		thread_ready(kb_thread);
 	}