diff --git a/lib/src/repo.rs b/lib/src/repo.rs
index ad555b4f5..43d395d4c 100644
--- a/lib/src/repo.rs
+++ b/lib/src/repo.rs
@@ -293,31 +293,16 @@ impl ReadonlyRepo {
     }
 
     pub fn shortest_unique_id_prefix_len(&self, target_id_bytes: &[u8]) -> usize {
-        let root_commit_id = self.store().root_commit_id();
-        let root_change_id = self.store().root_change_id();
-        if target_id_bytes == root_commit_id.as_bytes()
-            || target_id_bytes == root_change_id.as_bytes()
-        {
-            // The root change/commit ids share the same prefix, and they are found in both
-            // indices with different lengths. So we have to feed bytes of valid lengths.
-            cmp::max(
-                self.index()
-                    .shortest_unique_commit_id_prefix_len(root_commit_id),
-                self.change_id_index()
-                    .shortest_unique_prefix_len(root_change_id),
-            )
-        } else {
-            // For `len = index.shortest(id)`, a prefix of length `len` will disambiguate
-            // `id` from all other ids in the index. This will be just as true for
-            // `max(len, anything_else)`, so a max of such lengths will disambiguate in all
-            // indices.
-            cmp::max(
-                self.index()
-                    .shortest_unique_commit_id_prefix_len(&CommitId::from_bytes(target_id_bytes)),
-                self.change_id_index()
-                    .shortest_unique_prefix_len(&ChangeId::from_bytes(target_id_bytes)),
-            )
-        }
+        // For `len = index.shortest(id)`, a prefix of length `len` will disambiguate
+        // `id` from all other ids in the index. This will be just as true for
+        // `max(len, anything_else)`, so a max of such lengths will disambiguate in all
+        // indices.
+        cmp::max(
+            self.index()
+                .shortest_unique_commit_id_prefix_len(&CommitId::from_bytes(target_id_bytes)),
+            self.change_id_index()
+                .shortest_unique_prefix_len(&ChangeId::from_bytes(target_id_bytes)),
+        )
     }
 
     pub fn store(&self) -> &Arc<Store> {