diff --git a/evm/src/main/java/org/hyperledger/besu/evm/blockhash/BlockHashLookup.java b/evm/src/main/java/org/hyperledger/besu/evm/blockhash/BlockHashLookup.java
index eb1f8c43b0c..cd27843de9b 100644
--- a/evm/src/main/java/org/hyperledger/besu/evm/blockhash/BlockHashLookup.java
+++ b/evm/src/main/java/org/hyperledger/besu/evm/blockhash/BlockHashLookup.java
@@ -27,6 +27,11 @@
  */
 public interface BlockHashLookup extends BiFunction<MessageFrame, Long, Hash> {
 
+  /**
+   * How far back from the current block are hash queries valid for? Default is 256.
+   *
+   * @return The number of blocks before the current that should return a hash value.
+   */
   default long getLookback() {
     return 256L;
   }