diff --git a/src/channel.c b/src/channel.c
index 50dd180..af282cd 100644
--- a/src/channel.c
+++ b/src/channel.c
@@ -786,6 +786,7 @@
 
 	if ((id > 0 && tv->v_type == VAR_NUMBER && tv->vval.v_number == id)
 	      || (id <= 0 && (tv->v_type != VAR_NUMBER
+			       || tv->vval.v_number == 0
 			       || tv->vval.v_number != channel->ch_block_id)))
 	{
 	    *rettv = item->value;