Index: src/libcfa/concurrency/mutex.c
===================================================================
--- src/libcfa/concurrency/mutex.c	(revision 6c7099a9d37b5dcf81fe7ee2739fef0763b162e6)
+++ src/libcfa/concurrency/mutex.c	(revision 8cc7dd1d4cd96353976cd8249f7631ab4aa88341)
@@ -167,4 +167,5 @@
 	}
 	BlockInternal( __unlock );
+	lock(l);
 }