diff --git a/buddy/src/fdd.c b/buddy/src/fdd.c
index 46c1ba75898042cae5c88e167942cc723b0abefb..7085530f0fd52e7407dd5216bb3bd650362d1bae 100644
--- a/buddy/src/fdd.c
+++ b/buddy/src/fdd.c
@@ -954,6 +954,8 @@ int fdd_intaddvarblock(int first, int last, int fixed)
       res = tmp;
    }
 
+   bdd_addref(res); // Added by Jaco van de Pol, 25 march 2010
+
    err = bdd_addvarblock(res, fixed);
 
    bdd_delref(res);