Index: src/libcfa/concurrency/kernel.c
===================================================================
--- src/libcfa/concurrency/kernel.c	(revision dafdbe72fd669e1ca4ecdbf4c5fda0a85f3dab50)
+++ src/libcfa/concurrency/kernel.c	(revision f6f0d06fa9fd70fbb099213ae2c6902e2f6e039f)
@@ -16,4 +16,5 @@
 //C Includes
 #include <stddef.h>
+#include <errno.h>
 extern "C" {
 #include <stdio.h>