diff --git a/configs/mainnet.yaml b/configs/mainnet.yaml
index f5f38de5e..6475d491e 100644
--- a/configs/mainnet.yaml
+++ b/configs/mainnet.yaml
@@ -214,6 +214,8 @@ MAX_REVEAL_LATENESS_DECREMENT: 128
 # 2**8 (= 256)
 MAX_CUSTODY_KEY_REVEALS: 256
 MAX_EARLY_DERIVED_SECRET_REVEALS: 1
+MAX_CUSTODY_CHUNK_CHALLENGES: 4
+MAX_CUSTODY_CHUNK_CHALLENGE_RESP: 16
 MAX_CUSTODY_SLASHINGS: 1
 
 # Reward and penalty quotients
diff --git a/configs/minimal.yaml b/configs/minimal.yaml
index 1b5aac5f6..89e2a7eae 100644
--- a/configs/minimal.yaml
+++ b/configs/minimal.yaml
@@ -215,6 +215,8 @@ CUSTODY_PERIOD_TO_RANDAO_PADDING: 8
 # 2**8 (= 256)
 MAX_CUSTODY_KEY_REVEALS: 256
 MAX_EARLY_DERIVED_SECRET_REVEALS: 1
+MAX_CUSTODY_CHUNK_CHALLENGES: 2
+MAX_CUSTODY_CHUNK_CHALLENGE_RESP: 8
 MAX_CUSTODY_SLASHINGS: 1
 
 # Reward and penalty quotients
diff --git a/specs/phase1/beacon-chain.md b/specs/phase1/beacon-chain.md
index 27a9229dd..e48c99c4a 100644
--- a/specs/phase1/beacon-chain.md
+++ b/specs/phase1/beacon-chain.md
@@ -215,9 +215,11 @@ class BeaconBlockBody(Container):
     deposits: List[Deposit, MAX_DEPOSITS]
     voluntary_exits: List[SignedVoluntaryExit, MAX_VOLUNTARY_EXITS]
     # Custody game
-    custody_slashings: List[SignedCustodySlashing, MAX_CUSTODY_SLASHINGS]
+    chunk_challenges: List[CustodyChunkResponse, MAX_CUSTODY_CHUNK_CHALLENGES]
+    chunk_challenge_responses: List[CustodyChunkResponse, MAX_CUSTODY_CHUNK_CHALLENGE_RESPONSES]
     custody_key_reveals: List[CustodyKeyReveal, MAX_CUSTODY_KEY_REVEALS]
     early_derived_secret_reveals: List[EarlyDerivedSecretReveal, MAX_EARLY_DERIVED_SECRET_REVEALS]
+    custody_slashings: List[SignedCustodySlashing, MAX_CUSTODY_SLASHINGS]
     # Shards
     shard_transitions: Vector[ShardTransition, MAX_SHARDS]
     # Light clients
diff --git a/specs/phase1/custody-game.md b/specs/phase1/custody-game.md
index 96a7f5616..08893ef53 100644
--- a/specs/phase1/custody-game.md
+++ b/specs/phase1/custody-game.md
@@ -81,6 +81,7 @@ This document details the beacon chain additions and changes in Phase 1 of Ether
 | `MAX_CUSTODY_KEY_REVEALS` | `2**8` (= 256) |
 | `MAX_EARLY_DERIVED_SECRET_REVEALS` | `1` |
 | `MAX_CUSTODY_CHUNK_CHALLENGES` | `2**2` (= 4) |
+| `MAX_CUSTODY_CHUNK_CHALLENGE_RESPONSES` | `2**4` (= 16) |
 | `MAX_CUSTODY_SLASHINGS` | `1` |
 
 ### Reward and penalty quotients
@@ -297,6 +298,8 @@ def process_custody_game_operations(state: BeaconState, body: BeaconBlockBody) -
         for operation in operations:
             fn(state, operation)
 
+    for_ops(body.chunk_challenges, process_chunk_challenge)
+    for_ops(body.chunk_challenge_responses, process_chunk_challenge)
     for_ops(body.custody_key_reveals, process_custody_key_reveal)
     for_ops(body.early_derived_secret_reveals, process_early_derived_secret_reveal)
     for_ops(body.custody_slashings, process_custody_slashing)
@@ -304,10 +307,6 @@ def process_custody_game_operations(state: BeaconState, body: BeaconBlockBody) -
 
 #### Chunk challenges
 
-Verify that `len(block.body.custody_chunk_challenges) <= MAX_CUSTODY_CHUNK_CHALLENGES`.
-
-For each `challenge` in `block.body.custody_chunk_challenges`, run the following function:
-
 ```python
 def process_chunk_challenge(state: BeaconState, challenge: CustodyChunkChallenge) -> None:
     # Verify the attestation