diff --git a/blockservice.go b/blockservice.go
index 9cf96a8667b9dd5d9d90b29378a8c96eaf4a6803..33f69141c615e461ee3e9a97cd95584f4e036efb 100644
--- a/blockservice.go
+++ b/blockservice.go
@@ -282,18 +282,16 @@ func getBlocks(ctx context.Context, ks []cid.Cid, bs blockstore.Blockstore, fget
 		}
 
 		if !allValid {
-			ks2 := make([]cid.Cid, len(ks))
-			k := 0
+			ks2 := make([]cid.Cid, 0, len(ks))
 			for _, c := range ks {
 				// hash security
 				if err := verifcid.ValidateCid(c); err == nil {
-					ks2[k] = c
-					k++
+					ks2 = append(ks2, c)
 				} else {
 					log.Errorf("unsafe CID (%s) passed to blockService.GetBlocks: %s", c, err)
 				}
 			}
-			ks = ks2[:k]
+			ks = ks2
 		}
 
 		var misses []cid.Cid