diff --git a/src/opt/fret/fretMain.c b/src/opt/fret/fretMain.c
index f742cda03..e7995bf52 100644
--- a/src/opt/fret/fretMain.c
+++ b/src/opt/fret/fretMain.c
@@ -202,8 +202,9 @@ Abc_FlowRetime_MinReg( Abc_Ntk_t * pNtk, int fVerbose,
     pNtk = Abc_FlowRetime_NtkSilentRestrash( pNtk, 1 );
   }
   
+  i = Abc_NtkLevel(pNtk);
   vprintf("\tfinal reg count = %d\n", Abc_NtkLatchNum(pNtk));
-  vprintf("\tfinal levels = %d\n", Abc_NtkLevel(pNtk));
+  vprintf("\tfinal levels = %d\n", i);
 
 #if defined(DEBUG_CHECK)
   Abc_NtkDoCheck( pNtk );
@@ -1380,4 +1381,3 @@ void Abc_ObjPrintNeighborhood( Abc_Obj_t *pObj, int depth ) {
   Vec_PtrFree(vNodes);
 }
 ABC_NAMESPACE_IMPL_END
-
diff --git a/src/opt/fret/fretTime.c b/src/opt/fret/fretTime.c
index 9d55fc929..67fcabf8c 100644
--- a/src/opt/fret/fretTime.c
+++ b/src/opt/fret/fretTime.c
@@ -94,14 +94,13 @@ void Abc_FlowRetime_ConstrainConserv( Abc_Ntk_t * pNtk ) {
 
   // clear all exact constraints
   pManMR->nExactConstraints = 0;
-  while( Vec_PtrSize( pManMR->vExactNodes )) {
-    pObj = (Abc_Obj_t*)Vec_PtrPop( pManMR->vExactNodes );
-    
+  Abc_NtkForEachObj( pNtk, pObj, i ) {
     if ( Vec_PtrSize( FTIMEEDGES(pObj) )) {
       pArray =  Vec_PtrReleaseArray( FTIMEEDGES(pObj) );
       ABC_FREE( pArray );
     }
   }
+  Vec_PtrClear( pManMR->vExactNodes );
 
 #if !defined(IGNORE_TIMING)
   if (pManMR->fIsForward) {