diff --git a/src/aig/gia/giaUtil.c b/src/aig/gia/giaUtil.c
index d94a04123..b9a502209 100644
--- a/src/aig/gia/giaUtil.c
+++ b/src/aig/gia/giaUtil.c
@@ -1211,7 +1211,8 @@ int Gia_ManFindFailedPoCex( Gia_Man_t * pAig, Abc_Cex_t * p, int nOutputs )
     assert( iBit == p->nBits );
     // figure out the number of failed output
     RetValue = -1;
-    for ( i = Gia_ManPoNum(pAig) - 1; i >= nOutputs; i-- )
+//    for ( i = Gia_ManPoNum(pAig) - 1; i >= nOutputs; i-- )
+    for ( i = nOutputs; i < Gia_ManPoNum(pAig); i++ )
     {
         if ( Gia_ManPo(pAig, i)->fMark0 )
         {