diff --git a/ethcore/src/blockchain/blockchain.rs b/ethcore/src/blockchain/blockchain.rs
index feedf1247c6..2e0cb1557e8 100644
--- a/ethcore/src/blockchain/blockchain.rs
+++ b/ethcore/src/blockchain/blockchain.rs
@@ -27,14 +27,14 @@ use parking_lot::{Mutex, RwLock};
 use bytes::Bytes;
 use rlp::*;
 use header::*;
-use super::extras::*;
 use transaction::*;
 use views::*;
 use log_entry::{LogEntry, LocalizedLogEntry};
 use receipt::Receipt;
-use blooms::BloomGroup;
-use blockchain::block_info::{BlockInfo, BlockLocation, BranchBecomingCanonChainData};
+use blooms::{BloomGroup, GroupPosition};
 use blockchain::best_block::{BestBlock, BestAncientBlock};
+use blockchain::block_info::{BlockInfo, BlockLocation, BranchBecomingCanonChainData};
+use blockchain::extras::{BlockReceipts, BlockDetails, TransactionAddress, EPOCH_KEY_PREFIX, EpochTransitions};
 use types::blockchain_info::BlockChainInfo;
 use types::tree_route::TreeRoute;
 use blockchain::update::ExtrasUpdate;
@@ -163,13 +163,13 @@ enum CacheId {
 	BlockDetails(H256),
 	BlockHashes(BlockNumber),
 	TransactionAddresses(H256),
-	BlocksBlooms(LogGroupPosition),
+	BlocksBlooms(GroupPosition),
 	BlockReceipts(H256),
 }
 
 impl bc::group::BloomGroupDatabase for BlockChain {
 	fn blooms_at(&self, position: &bc::group::GroupPosition) -> Option<bc::group::BloomGroup> {
-		let position = LogGroupPosition::from(position.clone());
+		let position = GroupPosition::from(position.clone());
 		let result = self.db.read_with_cache(db::COL_EXTRA, &self.blocks_blooms, &position).map(Into::into);
 		self.cache_man.lock().note_used(CacheId::BlocksBlooms(position));
 		result
@@ -199,7 +199,7 @@ pub struct BlockChain {
 	block_details: RwLock<HashMap<H256, BlockDetails>>,
 	block_hashes: RwLock<HashMap<BlockNumber, H256>>,
 	transaction_addresses: RwLock<HashMap<H256, TransactionAddress>>,
-	blocks_blooms: RwLock<HashMap<LogGroupPosition, BloomGroup>>,
+	blocks_blooms: RwLock<HashMap<GroupPosition, BloomGroup>>,
 	block_receipts: RwLock<HashMap<H256, BlockReceipts>>,
 
 	db: Arc<KeyValueDB>,
@@ -1260,7 +1260,7 @@ impl BlockChain {
 	/// Later, BloomIndexer is used to map bloom location on filter layer (BloomIndex)
 	/// to bloom location in database (BlocksBloomLocation).
 	///
-	fn prepare_block_blooms_update(&self, block_bytes: &[u8], info: &BlockInfo) -> HashMap<LogGroupPosition, BloomGroup> {
+	fn prepare_block_blooms_update(&self, block_bytes: &[u8], info: &BlockInfo) -> HashMap<GroupPosition, BloomGroup> {
 		let block = BlockView::new(block_bytes);
 		let header = block.header_view();
 
diff --git a/ethcore/src/blockchain/extras.rs b/ethcore/src/blockchain/extras.rs
index d49d5c8d580..97583a693a6 100644
--- a/ethcore/src/blockchain/extras.rs
+++ b/ethcore/src/blockchain/extras.rs
@@ -18,7 +18,6 @@
 
 use std::ops;
 use std::io::Write;
-use bloomchain;
 use blooms::{GroupPosition, BloomGroup};
 use db::Key;
 use engines::epoch::{Transition as EpochTransition};
@@ -97,32 +96,17 @@ impl ops::Deref for LogGroupKey {
 	}
 }
 
-#[derive(Debug, PartialEq, Eq, Hash, Clone)]
-pub struct LogGroupPosition(GroupPosition);
-
-impl From<bloomchain::group::GroupPosition> for LogGroupPosition {
-	fn from(position: bloomchain::group::GroupPosition) -> Self {
-		LogGroupPosition(From::from(position))
-	}
-}
-
-impl HeapSizeOf for LogGroupPosition {
-	fn heap_size_of_children(&self) -> usize {
-		self.0.heap_size_of_children()
-	}
-}
-
-impl Key<BloomGroup> for LogGroupPosition {
+impl Key<BloomGroup> for GroupPosition {
 	type Target = LogGroupKey;
 
 	fn key(&self) -> Self::Target {
 		let mut result = [0u8; 6];
 		result[0] = ExtrasIndex::BlocksBlooms as u8;
-		result[1] = self.0.level;
-		result[2] = (self.0.index >> 24) as u8;
-		result[3] = (self.0.index >> 16) as u8;
-		result[4] = (self.0.index >> 8) as u8;
-		result[5] = self.0.index as u8;
+		result[1] = self.level;
+		result[2] = (self.index >> 24) as u8;
+		result[3] = (self.index >> 16) as u8;
+		result[4] = (self.index >> 8) as u8;
+		result[5] = self.index as u8;
 		LogGroupKey(result)
 	}
 }
diff --git a/ethcore/src/blockchain/mod.rs b/ethcore/src/blockchain/mod.rs
index 55a67e2b65e..062068c704d 100644
--- a/ethcore/src/blockchain/mod.rs
+++ b/ethcore/src/blockchain/mod.rs
@@ -18,10 +18,10 @@
 
 mod best_block;
 mod block_info;
-pub mod blockchain;
+mod blockchain;
 mod cache;
 mod config;
-pub mod extras;
+mod extras;
 mod import_route;
 mod update;
 
@@ -31,5 +31,6 @@ pub mod generator;
 pub use self::blockchain::{BlockProvider, BlockChain};
 pub use self::cache::CacheSize;
 pub use self::config::Config;
-pub use types::tree_route::TreeRoute;
+pub use self::extras::{BlockReceipts, BlockDetails, TransactionAddress};
 pub use self::import_route::ImportRoute;
+pub use types::tree_route::TreeRoute;
diff --git a/ethcore/src/blockchain/update.rs b/ethcore/src/blockchain/update.rs
index a54fed052f6..467ccc8d17b 100644
--- a/ethcore/src/blockchain/update.rs
+++ b/ethcore/src/blockchain/update.rs
@@ -2,8 +2,8 @@ use std::collections::HashMap;
 use ethereum_types::H256;
 use header::BlockNumber;
 use blockchain::block_info::BlockInfo;
-use blooms::BloomGroup;
-use super::extras::{BlockDetails, BlockReceipts, TransactionAddress, LogGroupPosition};
+use blockchain::extras::{BlockDetails, BlockReceipts, TransactionAddress};
+use blooms::{BloomGroup, GroupPosition};
 
 /// Block extras update info.
 pub struct ExtrasUpdate<'a> {
@@ -20,7 +20,7 @@ pub struct ExtrasUpdate<'a> {
 	/// Modified block receipts.
 	pub block_receipts: HashMap<H256, BlockReceipts>,
 	/// Modified blocks blooms.
-	pub blocks_blooms: HashMap<LogGroupPosition, BloomGroup>,
+	pub blocks_blooms: HashMap<GroupPosition, BloomGroup>,
 	/// Modified transaction addresses (None signifies removed transactions).
 	pub transactions_addresses: HashMap<H256, Option<TransactionAddress>>,
 }
diff --git a/ethcore/src/client/client.rs b/ethcore/src/client/client.rs
index 08faf286f84..8eb8c483349 100644
--- a/ethcore/src/client/client.rs
+++ b/ethcore/src/client/client.rs
@@ -34,8 +34,7 @@ use kvdb::{DBValue, KeyValueDB, DBTransaction};
 // other
 use ethereum_types::{H256, Address, U256};
 use block::*;
-use blockchain::{BlockChain, BlockProvider,  TreeRoute, ImportRoute};
-use blockchain::extras::TransactionAddress;
+use blockchain::{BlockChain, BlockProvider,  TreeRoute, ImportRoute, TransactionAddress};
 use client::ancient_import::AncientVerifier;
 use client::Error as ClientError;
 use client::{
diff --git a/ethcore/src/client/test_client.rs b/ethcore/src/client/test_client.rs
index 0fec09014f8..f1561f3e6ab 100644
--- a/ethcore/src/client/test_client.rs
+++ b/ethcore/src/client/test_client.rs
@@ -33,7 +33,7 @@ use rlp::*;
 use ethkey::{Generator, Random};
 use tempdir::TempDir;
 use transaction::{self, Transaction, LocalizedTransaction, PendingTransaction, SignedTransaction, Action};
-use blockchain::TreeRoute;
+use blockchain::{TreeRoute, BlockReceipts};
 use client::{
 	BlockChainClient, MiningBlockChainClient, BlockChainInfo, BlockStatus, BlockId,
 	TransactionId, UncleId, TraceId, TraceFilter, LastHashes, CallAnalytics, BlockImportError,
@@ -44,7 +44,6 @@ use header::{Header as BlockHeader, BlockNumber};
 use filter::Filter;
 use log_entry::LocalizedLogEntry;
 use receipt::{Receipt, LocalizedReceipt, TransactionOutcome};
-use blockchain::extras::BlockReceipts;
 use error::{ImportResult, Error as EthcoreError};
 use evm::{Factory as EvmFactory, VMType};
 use vm::Schedule;
diff --git a/ethcore/src/client/trace.rs b/ethcore/src/client/trace.rs
index 4236aeaf420..75e0fe34a1e 100644
--- a/ethcore/src/client/trace.rs
+++ b/ethcore/src/client/trace.rs
@@ -4,8 +4,7 @@
 use ethereum_types::H256;
 use header::BlockNumber;
 use trace::DatabaseExtras as TraceDatabaseExtras;
-use blockchain::{BlockChain, BlockProvider};
-use blockchain::extras::TransactionAddress;
+use blockchain::{BlockChain, BlockProvider, TransactionAddress};
 pub use types::trace_filter::Filter;
 
 impl TraceDatabaseExtras for BlockChain {
diff --git a/ethcore/src/verification/verification.rs b/ethcore/src/verification/verification.rs
index 10cd3f6cbcc..5e3bc7ea2ba 100644
--- a/ethcore/src/verification/verification.rs
+++ b/ethcore/src/verification/verification.rs
@@ -337,7 +337,7 @@ mod tests {
 
 	use std::collections::{BTreeMap, HashMap};
 	use ethereum_types::{H256, Bloom, U256};
-	use blockchain::extras::{BlockDetails, TransactionAddress, BlockReceipts};
+	use blockchain::{BlockDetails, TransactionAddress, BlockReceipts};
 	use encoded;
 	use hash::keccak;
 	use engines::EthEngine;