Index: src/libcfa/concurrency/kernel.c
===================================================================
--- src/libcfa/concurrency/kernel.c	(revision 3ce0d4400c0b556469634be2ec688b0fba8ddbee)
+++ src/libcfa/concurrency/kernel.c	(revision d885a586d0d5310ea73c5538209f473948be8c75)
@@ -663,4 +663,5 @@
 	__cfaabi_dbg_print_safe("Kernel : Processor %p ready to sleep\n", this);
 
+	verify( ({int sval = 0; sem_getvalue(&this->idleLock, &sval); sval; }) < 65536);
 	sem_wait(&idleLock);
 
@@ -678,4 +679,5 @@
 	__cfaabi_dbg_print_safe("Kernel : Waking up processor %p\n", this);
 	sem_post(&this->idleLock);
+	verify( ({int sval = 0; sem_getvalue(&this->idleLock, &sval); sval; }) < 65536);
 }