diff --git a/notary/internal/tlog/tile.go b/notary/internal/tlog/tile.go
index 7c6ec23..855cb1e 100644
--- a/notary/internal/tlog/tile.go
+++ b/notary/internal/tlog/tile.go
@@ -299,8 +299,7 @@
 	// the parents are being fetched anyway.
 	indexTileOrder := make([]int, len(indexes))
 	for i, x := range indexes {
-		level, n := SplitStoredHashIndex(x)
-		if n<<uint(level) >= r.tree.N {
+		if x >= StoredHashIndex(0, r.tree.N) {
 			return nil, fmt.Errorf("indexes not in tree")
 		}
 
diff --git a/notary/internal/tlog/tlog_test.go b/notary/internal/tlog/tlog_test.go
index a225a0f..cfc1233 100644
--- a/notary/internal/tlog/tlog_test.go
+++ b/notary/internal/tlog/tlog_test.go
@@ -166,6 +166,11 @@
 			}
 		}
 
+		// Check that ReadHashes will give an error if the index is not in the tree.
+		if _, err := thr.ReadHashes([]int64{(i + 1) * 2}); err == nil {
+			t.Fatalf("TileHashReader(%d).ReadHashes(%d) for index not in tree <nil>, want err", i, i+1)
+		}
+
 		// Check that tree proofs work, for all trees so far, using TileReader.
 		// To prove a tree that way, all you have to do is compute and verify its hash.
 		for j := int64(0); j <= i; j++ {