diff --git a/fork_choice/safe-block.md b/fork_choice/safe-block.md
index 127002b15..490d24538 100644
--- a/fork_choice/safe-block.md
+++ b/fork_choice/safe-block.md
@@ -44,3 +44,5 @@ def get_safe_execution_payload_hash(store: Store) -> Hash32:
     else:
         return Hash32()
 ```
+
+*Note*: This helper uses beacon block container extended in [Bellatrix](../specs/bellatrix/beacon-chain.md).
diff --git a/specs/bellatrix/fork-choice.md b/specs/bellatrix/fork-choice.md
index 305d58a57..60a54da9c 100644
--- a/specs/bellatrix/fork-choice.md
+++ b/specs/bellatrix/fork-choice.md
@@ -75,7 +75,8 @@ As per EIP-3675, before a post-transition block is finalized, `notify_forkchoice
 
 ##### `safe_block_hash`
 
-The `safe_block_hash` parameter MUST be set to return value of `get_safe_execution_payload_hash(store: Store)` function.
+The `safe_block_hash` parameter MUST be set to return value of
+[`get_safe_execution_payload_hash(store: Store)`](../../fork_choice/safe-block.md#get_safe_execution_payload_hash) function.
 
 ## Helpers