Index: libcfa/src/concurrency/kernel.cfa
===================================================================
--- libcfa/src/concurrency/kernel.cfa	(revision 262fafd9abd78b79c089ca674311367f639b05e0)
+++ libcfa/src/concurrency/kernel.cfa	(revision d080549e6c92f89e0bef8117f6dbc03337bb9b72)
@@ -686,6 +686,7 @@
 	eventfd_t val;
 	val = 1;
-	eventfd_write( this->idle_wctx.evfd, val );
-
+	__attribute__((unused)) int ret = eventfd_write( this->idle_wctx.evfd, val );
+
+	/* paranoid */ verifyf( ret == 0, "Expected return to be 0, was %d\n", ret );
 	/* paranoid */ verify( ! __preemption_enabled() );
 }