diff --git a/src/aig/gia/giaMf.c b/src/aig/gia/giaMf.c
index 7c67fb88d..ecea3955d 100644
--- a/src/aig/gia/giaMf.c
+++ b/src/aig/gia/giaMf.c
@@ -1600,14 +1600,14 @@ static inline int Mf_CutAreaRefed( Mf_Man_t * p, int * pCut )
 {
     int Ela1 = Mf_CutDeref_rec( p, pCut );
     int Ela2 = Mf_CutRef_rec( p, pCut );
-    //assert( Ela1 == Ela2 );
+    assert( Ela1 == Ela2 );
     return Ela1;
 }
 static inline int Mf_CutAreaDerefed( Mf_Man_t * p, int * pCut )
 {
     int Ela1 = Mf_CutRef_rec( p, pCut );
     int Ela2 = Mf_CutDeref_rec( p, pCut );
-    //assert( Ela1 == Ela2 );
+    assert( Ela1 == Ela2 );
     return Ela1;
 }
 static inline float Mf_CutFlow( Mf_Man_t * p, int * pCut, int * pTime )
diff --git a/src/aig/gia/giaUtil.c b/src/aig/gia/giaUtil.c
index b8f33b693..2409df2e3 100644
--- a/src/aig/gia/giaUtil.c
+++ b/src/aig/gia/giaUtil.c
@@ -1272,9 +1272,9 @@ int Gia_NodeMffcMapping( Gia_Man_t * p )
     Vec_IntFill( vMapping, Gia_ManObjNum(p), 0 );
     pRefsOld = p->pRefs; p->pRefs = NULL;
     Gia_ManCreateRefs( p ); 
-    p->pRefs = pRefsOld;
     Gia_ManForEachCoDriverId( p, Id, i )
         Count += Gia_NodeMffcMapping_rec( p, Id, vMapping, vSupp );
+    p->pRefs = pRefsOld;
     Vec_IntFree( vSupp );
     p->vMapping = vMapping;
     //printf( "Mapping is %.2fx larger than AIG manager.\n", 1.0*Vec_IntSize(vMapping)/Gia_ManObjNum(p) );