diff --git a/specs/core/1_shard-data-chains.md b/specs/core/1_shard-data-chains.md
index 477dce44f..6edc5daba 100644
--- a/specs/core/1_shard-data-chains.md
+++ b/specs/core/1_shard-data-chains.md
@@ -106,8 +106,8 @@ This document describes the shard transition function (data layer only) and the
 ### `Crosslink`
 
 ```python
+# Crosslink is a placeholder to appease the build script until phase 1 is reworked
 class Crosslink(Container):
-    # STUB: placeholder data structure while reworking phase 0
     shard: Shard
 ```
  
diff --git a/test_libs/pyspec/eth2spec/test/helpers/block.py b/test_libs/pyspec/eth2spec/test/helpers/block.py
index 2682a0c82..779f2e1cf 100644
--- a/test_libs/pyspec/eth2spec/test/helpers/block.py
+++ b/test_libs/pyspec/eth2spec/test/helpers/block.py
@@ -14,7 +14,7 @@ def sign_block(spec, state, block, proposer_index=None):
         if block.slot == state.slot:
             proposer_index = spec.get_beacon_proposer_index(state)
         else:
-            if spec.compute_epoch_of_slot(state.slot) + 1 > spec.compute_epoch_of_slot(block.slot):
+            if spec.compute_epoch_at_slot(state.slot) + 1 > spec.compute_epoch_at_slot(block.slot):
                 print("warning: block slot far away, and no proposer index manually given."
                       " Signing block is slow due to transition for proposer index calculation.")
             # use stub state to get proposer index of future slot
@@ -26,10 +26,10 @@ def sign_block(spec, state, block, proposer_index=None):
 
     block.body.randao_reveal = bls_sign(
         privkey=privkey,
-        message_hash=hash_tree_root(spec.compute_epoch_of_slot(block.slot)),
+        message_hash=hash_tree_root(spec.compute_epoch_at_slot(block.slot)),
         domain=spec.get_domain(
             state,
-            message_epoch=spec.compute_epoch_of_slot(block.slot),
+            message_epoch=spec.compute_epoch_at_slot(block.slot),
             domain_type=spec.DOMAIN_RANDAO,
         )
     )
@@ -39,7 +39,7 @@ def sign_block(spec, state, block, proposer_index=None):
         domain=spec.get_domain(
             state,
             spec.DOMAIN_BEACON_PROPOSER,
-            spec.compute_epoch_of_slot(block.slot)))
+            spec.compute_epoch_at_slot(block.slot)))
 
 
 def apply_empty_block(spec, state):