Index: src/libcfa/concurrency/mutex.c
===================================================================
--- src/libcfa/concurrency/mutex.c	(revision 0c674e80fb16ad200b53123b9c7451e3a60db3ae)
+++ src/libcfa/concurrency/mutex.c	(revision 8cc7dd1d4cd96353976cd8249f7631ab4aa88341)
@@ -167,4 +167,5 @@
 	}
 	BlockInternal( __unlock );
+	lock(l);
 }