Index: src/libcfa/concurrency/preemption.c
===================================================================
--- src/libcfa/concurrency/preemption.c	(revision dbe77568c1a9061d112464437d381639ef72505b)
+++ src/libcfa/concurrency/preemption.c	(revision e2f7bc3f75223dd833821863a884160e203bb19d)
@@ -328,4 +328,18 @@
 		siginfo_t info;
 		int sig = sigwaitinfo( &mask, &info );
+
+		if( sig < 0 ) {
+			//Error!
+			int err = errno;
+			switch( err ) {
+				case EAGAIN :
+				case EINTR :
+					continue;
+       			case EINVAL :
+				 	abortf("Timeout was invalid.");
+				default:
+				 	abortf("Unhandled error %d", err);
+			}
+		}
 
 		// If another signal arrived something went wrong