diff --git a/core/store/src/trie/trie_recording.rs b/core/store/src/trie/trie_recording.rs
index c81d1133e36..cc411db5b3f 100644
--- a/core/store/src/trie/trie_recording.rs
+++ b/core/store/src/trie/trie_recording.rs
@@ -67,6 +67,7 @@ mod trie_recording_tests {
         /// The keys that we should be using to call get_optimized_ref() on the
         /// trie with.
         keys_to_get_ref: Vec<Vec<u8>>,
+        /// The keys to be updated after trie reads.
         updates: Vec<(Vec<u8>, Option<Vec<u8>>)>,
         state_root: StateRoot,
     }