Index: src/libcfa/concurrency/kernel.c
===================================================================
--- src/libcfa/concurrency/kernel.c	(revision 249d6e622aa9420065e79f351b95b2bfd0d4cacc)
+++ src/libcfa/concurrency/kernel.c	(revision 1ddbf3b62f7b382b7646fdf54b247335ad770718)
@@ -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);
 }