diff --git a/iguana/iguana_blocks.c b/iguana/iguana_blocks.c
index e6cd7a80b..93a993063 100755
--- a/iguana/iguana_blocks.c
+++ b/iguana/iguana_blocks.c
@@ -622,7 +622,7 @@ struct iguana_block *_iguana_chainlink(struct supernet_info *myinfo,struct iguan
             return(0);
         }
         //char str[65]; printf("extend? %s.h%d: %.15f vs %.15f ht.%d vs %d\n",bits256_str(str,block->RO.hash2),height,block->PoW,coin->blocks.hwmchain.PoW,height,coin->blocks.hwmchain.height);
-        if ( iguana_blockvalidate(myinfo,coin,&valid,newblock,0) < 0 || valid == 0 )
+        if ( height < 0 || iguana_blockvalidate(myinfo,coin,&valid,newblock,0) < 0 || valid == 0 )
             return(0);
         block->height = height;
         block->valid = 1;