diff --git a/eth2/types/src/chain_spec.rs b/eth2/types/src/chain_spec.rs
index d6eaa123d..9dec626d4 100644
--- a/eth2/types/src/chain_spec.rs
+++ b/eth2/types/src/chain_spec.rs
@@ -202,15 +202,12 @@ impl ChainSpec {
     pub fn minimal() -> Self {
         // Note: bootnodes to be updated when static nodes exist.
         let boot_nodes = vec![];
-        let genesis_slot = Slot::new(0);
 
         Self {
             target_committee_size: 4,
             shuffle_round_count: 10,
             min_genesis_active_validator_count: 64,
             max_epochs_per_crosslink: 4,
-            min_attestation_inclusion_delay: 2,
-            genesis_slot,
             network_id: 2, // lighthouse testnet network id
             boot_nodes,
             ..ChainSpec::mainnet()
@@ -221,15 +218,12 @@ impl ChainSpec {
     ///
     /// This allows us to customize a chain spec for interop testing.
     pub fn interop() -> Self {
-        let genesis_slot = Slot::new(0);
         let boot_nodes = vec![];
 
         Self {
             seconds_per_slot: 12,
             target_committee_size: 4,
             shuffle_round_count: 10,
-            min_attestation_inclusion_delay: 2,
-            genesis_slot,
             network_id: 13,
             boot_nodes,
             ..ChainSpec::mainnet()