diff --git a/beacon_chain/spec/beaconstate.nim b/beacon_chain/spec/beaconstate.nim
index c0de8db6e..919c1b7c5 100644
--- a/beacon_chain/spec/beaconstate.nim
+++ b/beacon_chain/spec/beaconstate.nim
@@ -227,12 +227,17 @@ func initialize_beacon_state_from_eth1*(
   state.randao_mixes.fill(eth1_block_hash)
 
   # Process deposits
-  let leaves = deposits.mapIt(it.data)
+  let
+    leaves = deposits.mapIt(it.data)
+    prefix_roots =
+      hash_tree_roots_prefix(leaves, 2'i64^DEPOSIT_CONTRACT_TREE_DEPTH)
   for i, deposit in deposits:
     let deposit_data_list = leaves[0..i]
-    state.eth1_data.deposit_root = hash_tree_root(
+    let prev_calc_method_deposit_root = hash_tree_root(
       sszList(deposit_data_list, 2'i64^DEPOSIT_CONTRACT_TREE_DEPTH))
 
+    state.eth1_data.deposit_root = prefix_roots[i]
+    doAssert state.eth1_data.deposit_root == prev_calc_method_deposit_root
     discard process_deposit(state, deposit, flags)
 
   # Process activations
diff --git a/beacon_chain/ssz.nim b/beacon_chain/ssz.nim
index 33f3be963..f0ea63cd0 100644
--- a/beacon_chain/ssz.nim
+++ b/beacon_chain/ssz.nim
@@ -73,7 +73,7 @@ proc init*(T: type SszReader,
            maxObjectSize = defaultMaxObjectSize): T =
   T(stream: stream, maxObjectSize: maxObjectSize)
 
-proc mount*(F: type SSZ, stream: ByteStreamVar, T: type): T =
+proc mount(F: type SSZ, stream: ByteStreamVar, T: type): T =
   mixin readValue
   var reader = init(SszReader, stream)
   reader.readValue(T)
@@ -166,7 +166,7 @@ template enumerateSubFields(holder, fieldVar, body: untyped) =
 
 func writeVarSizeType(w: var SszWriter, value: auto) {.gcsafe.}
 
-func beginRecord*(w: var SszWriter, TT: type): auto =
+func beginRecord(w: var SszWriter, TT: type): auto =
   type T = TT
   when isFixedSize(T):
     FixedSizedWriterCtx()
@@ -269,7 +269,7 @@ template fromSszBytes*[T; N](_: type TypeWithMaxLen[T, N],
   mixin fromSszBytes
   fromSszBytes(T, bytes)
 
-func fromSszBytes*(T: type BlsCurveType, bytes: openarray[byte]): auto =
+func fromSszBytes(T: type BlsCurveType, bytes: openarray[byte]): auto =
   init(T, bytes)
 
 proc readValue*(r: var SszReader, val: var auto) =
@@ -327,7 +327,7 @@ func getZeroHashWithoutSideEffect(idx: int): Eth2Digest =
   {.noSideEffect.}:
     zeroHashes[idx]
 
-func addChunk*(merkelizer: SszChunksMerkelizer, data: openarray[byte]) =
+func addChunk(merkelizer: SszChunksMerkelizer, data: openarray[byte]) =
   doAssert data.len > 0 and data.len <= bytesPerChunk
 
   if not getBitLE(merkelizer.totalChunks, 0):
@@ -350,7 +350,7 @@ func addChunk*(merkelizer: SszChunksMerkelizer, data: openarray[byte]) =
 
   inc merkelizer.totalChunks
 
-func getFinalHash*(merkelizer: SszChunksMerkelizer): Eth2Digest =
+func getFinalHash(merkelizer: SszChunksMerkelizer): Eth2Digest =
   let limit = merkelizer.limit
 
   if merkelizer.totalChunks == 0:
@@ -573,11 +573,23 @@ func hash_tree_root*(x: auto): Eth2Digest =
 
   trs "HASH TREE ROOT FOR ", name(type x), " = ", "0x", $result
 
+func hash_tree_roots_prefix*[T](lst: openarray[T], limit: auto):
+    seq[Eth2Digest] =
+  # This is a particular type's instantiation of a general fold, reduce,
+  # accumulation, prefix sums, etc family of operations. As long as that
+  # Eth1 deposit case is the only notable example -- the usual uses of a
+  # list involve, at some point, tree-hashing it -- finalized hashes are
+  # the only abstraction that escapes from this module this way.
+  var merkelizer = SszChunksMerkelizer(limit: uint64(limit))
+  for i, elem in lst:
+    merkelizer.addChunk(hash_tree_root(elem).data)
+    result.add mixInLength(merkelizer.getFinalHash(), i + 1)
+
 func lastFieldName(RecordType: type): string {.compileTime.} =
   enumAllSerializedFields(RecordType):
     result = fieldName
 
-func hasSigningRoot*(T: type): bool {.compileTime.} =
+func hasSigningRoot(T: type): bool {.compileTime.} =
   lastFieldName(T) == "signature"
 
 func signingRoot*(obj: object): Eth2Digest =
diff --git a/tests/simulation/vars.sh b/tests/simulation/vars.sh
index 7396a71dd..5fb061db7 100644
--- a/tests/simulation/vars.sh
+++ b/tests/simulation/vars.sh
@@ -1,15 +1,19 @@
 #!/bin/bash
 
+# https://github.com/koalaman/shellcheck/wiki/SC2034
+# shellcheck disable=2034
+true
+
 PWD_CMD="pwd"
 # get native Windows paths on Mingw
 uname | grep -qi mingw && PWD_CMD="pwd -W"
 
-cd $(dirname $0)
+cd "$(dirname "$0")"
 
 SIM_ROOT="$($PWD_CMD)"
 
 # Set a default value for the env vars usually supplied by a Makefile
-cd $(git rev-parse --show-toplevel)
+cd "$(git rev-parse --show-toplevel)"
 : ${GIT_ROOT:="$($PWD_CMD)"}
 cd - &>/dev/null
 
diff --git a/tests/testutil.nim b/tests/testutil.nim
index b0f998bce..bc4054396 100644
--- a/tests/testutil.nim
+++ b/tests/testutil.nim
@@ -17,7 +17,7 @@ func preset*(): string =
   " [Preset: " & const_preset & ']'
 
 when ValidatorPrivKey is BlsValue:
-  func makeFakeValidatorPrivKey*(i: int): ValidatorPrivKey =
+  func makeFakeValidatorPrivKey(i: int): ValidatorPrivKey =
     # 0 is not a valid BLS private key - 1000 helps interop with rust BLS library,
     # lighthouse.
     # TODO: switch to https://github.com/ethereum/eth2.0-pm/issues/60
@@ -25,14 +25,14 @@ when ValidatorPrivKey is BlsValue:
     var bytes = uint64(i + 1000).toBytesLE()
     copyMem(addr result.blsValue.x[0], addr bytes[0], sizeof(bytes))
 else:
-  func makeFakeValidatorPrivKey*(i: int): ValidatorPrivKey =
+  func makeFakeValidatorPrivKey(i: int): ValidatorPrivKey =
     # 0 is not a valid BLS private key - 1000 helps interop with rust BLS library,
     # lighthouse.
     # TODO: switch to https://github.com/ethereum/eth2.0-pm/issues/60
     var bytes = uint64(i + 1000).toBytesLE()
     copyMem(addr result.x[0], addr bytes[0], sizeof(bytes))
 
-func makeFakeHash*(i: int): Eth2Digest =
+func makeFakeHash(i: int): Eth2Digest =
   var bytes = uint64(i).toBytesLE()
   static: doAssert sizeof(bytes) <= sizeof(result.data)
   copyMem(addr result.data[0], addr bytes[0], sizeof(bytes))