diff --git a/beacon_chain/beacon_node.nim b/beacon_chain/beacon_node.nim
index 624426bc3..a7ea02e2e 100644
--- a/beacon_chain/beacon_node.nim
+++ b/beacon_chain/beacon_node.nim
@@ -414,8 +414,9 @@ proc proposeBlock(node: BeaconNode,
         slot: slot,
         parent_root: head.root,
         body: blockBody,
-        signature: ValidatorSig(), # we need the rest of the block first!
-      )
+        # TODO: This shouldn't be necessary if OpaqueBlob is the default
+        signature: ValidatorSig(kind: OpaqueBlob))
+
 
     var
       tmpState = hashedState
diff --git a/beacon_chain/spec/beaconstate.nim b/beacon_chain/spec/beaconstate.nim
index 635eb04a4..2a9a9b395 100644
--- a/beacon_chain/spec/beaconstate.nim
+++ b/beacon_chain/spec/beaconstate.nim
@@ -232,7 +232,9 @@ func initialize_beacon_state_from_eth1*(
       Eth1Data(block_hash: eth1_block_hash, deposit_count: uint64(len(deposits))),
     latest_block_header:
       BeaconBlockHeader(
-        body_root: hash_tree_root(BeaconBlockBody()),
+        body_root: hash_tree_root(BeaconBlockBody(
+          randao_reveal: BlsValue[Signature](kind: OpaqueBlob)
+        )),
         # TODO - Pure BLSSig cannot be zero: https://github.com/status-im/nim-beacon-chain/issues/374
         signature: BlsValue[Signature](kind: OpaqueBlob)
       )
@@ -284,10 +286,15 @@ proc is_valid_genesis_state*(state: BeaconState): bool =
 func get_initial_beacon_block*(state: BeaconState): BeaconBlock =
   BeaconBlock(
     slot: GENESIS_SLOT,
-    state_root: hash_tree_root(state)
+    state_root: hash_tree_root(state),
+    body: BeaconBlockBody(
+        # TODO: This shouldn't be necessary if OpaqueBlob is the default
+        randao_reveal: BlsValue[Signature](kind: OpaqueBlob)),
+    # TODO: This shouldn't be necessary if OpaqueBlob is the default
+    signature: BlsValue[Signature](kind: OpaqueBlob))
     # parent_root, randao_reveal, eth1_data, signature, and body automatically
     # initialized to default values.
-  )
+
 
 # https://github.com/ethereum/eth2.0-specs/blob/v0.8.3/specs/core/0_beacon-chain.md#get_attestation_data_slot
 func get_attestation_data_slot*(state: BeaconState,
diff --git a/beacon_chain/validator_pool.nim b/beacon_chain/validator_pool.nim
index b6d070e3b..bf6af9aa2 100644
--- a/beacon_chain/validator_pool.nim
+++ b/beacon_chain/validator_pool.nim
@@ -39,9 +39,8 @@ proc signBlockProposal*(v: AttachedValidator, state: BeaconState, slot: Slot,
         get_domain(state, DOMAIN_BEACON_PROPOSER, compute_epoch_of_slot(slot))
     result = bls_sign(v.privKey, blockRoot.data, domain)
   else:
-    # TODO:
-    # send RPC
-    discard
+    error "Unimplemented"
+    quit 1
 
 proc signAttestation*(v: AttachedValidator,
                       attestation: AttestationData,
@@ -59,9 +58,8 @@ proc signAttestation*(v: AttachedValidator,
 
     result = bls_sign(v.privKey, attestationRoot.data, domain)
   else:
-    # TODO:
-    # send RPC
-    discard
+    error "Unimplemented"
+    quit 1
 
 func genRandaoReveal*(k: ValidatorPrivKey, state: BeaconState, slot: Slot):
     ValidatorSig =
diff --git a/tests/test_interop.nim b/tests/test_interop.nim
index d13ed9653..96e6da356 100644
--- a/tests/test_interop.nim
+++ b/tests/test_interop.nim
@@ -1,7 +1,7 @@
 import
   unittest, stint, blscurve, stew/byteutils,
-  ../beacon_chain/interop,
-  ../beacon_chain/spec/[digest, crypto, helpers, datatypes]
+  ../beacon_chain/[extras, interop, ssz],
+  ../beacon_chain/spec/[beaconstate, digest, crypto, helpers, datatypes]
 
 # Interop test yaml, found here:
 # https://github.com/ethereum/eth2.0-pm/blob/a0b9d22fad424574b1307828f867b30237758468/interop/mocked_start/keygen_10_validators.yaml
@@ -134,3 +134,31 @@ suite "Interop":
 
       check:
         dep.sig == computed_sig
+
+  test "Interop genesis":
+    # Check against https://github.com/protolambda/zcli:
+    # zcli keys generate --to 64 | zcli genesis mock --genesis-time 1570500000 > /tmp/state.ssz
+    # zcli hash-tree-root /tmp.state.ssz
+    var deposits: seq[Deposit]
+
+    for i in 0..<64:
+      let
+        privKey = makeInteropPrivKey(i)
+      deposits.add(makeDeposit(privKey.pubKey(), privKey))
+
+    var
+      initialState = initialize_beacon_state_from_eth1(
+        eth1BlockHash, 1570500000, deposits, {skipValidation})
+
+    # https://github.com/ethereum/eth2.0-pm/tree/6e41fcf383ebeb5125938850d8e9b4e9888389b4/interop/mocked_start#create-genesis-state
+    initialState.genesis_time = 1570500000
+
+    let expected =
+      when const_preset == "minimal":
+        "029836dbceb95c20b101f8f44470604c0912e96949aaf1dd9ad41effd92abcbf"
+      elif const_preset == "mainnet":
+        "9cd22b0ea2ec836fef591d259f0d4273669cba4c82df32cf0aa55c388ff7e432"
+      else:
+        "unimplemented"
+    check:
+      hash_tree_root(initialState).data.toHex() == expected