diff --git a/iguana/iguana_unspents.c b/iguana/iguana_unspents.c
index 668523c40..e37f9ac76 100755
--- a/iguana/iguana_unspents.c
+++ b/iguana/iguana_unspents.c
@@ -650,7 +650,7 @@ struct iguana_bundle *iguana_externalspent(struct iguana_info *coin,bits256 *pre
                             iguana_ramchain_prefetch(coin,&spentbp->ramchain,prefetchflag);
                             spentbp->lastprefetch = now;
                         }
-                        else if ( (rand() % IGUANA_NUMHELPERS) == 0 && (duration > 1 || duration > (10 * coin->txidfind_totalmillis)/coin->txidfind_num) && now >= spentbp->lastprefetch )
+                        else if ( (rand() % IGUANA_NUMHELPERS) == 0 && (duration > 10 || duration > (10 * coin->txidfind_totalmillis)/coin->txidfind_num) && now >= spentbp->lastprefetch+coin->PREFETCHLAG )
                         {
                             printf("slow txidfind %.2f vs %.2f prefetch[%d] from.[%d] lag.%ld last.%u\n",duration,coin->txidfind_totalmillis/coin->txidfind_num,spentbp->hdrsi,ramchain->H.data->height/coin->chain->bundlesize,time(NULL) - spentbp->lastprefetch,spentbp->lastprefetch);
                             iguana_ramchain_prefetch(coin,&spentbp->ramchain,prefetchflag);