diff --git a/ethcore/src/client/client.rs b/ethcore/src/client/client.rs
index 92c996982..f0fdacfe8 100644
--- a/ethcore/src/client/client.rs
+++ b/ethcore/src/client/client.rs
@@ -61,7 +61,7 @@ use client::{
 	IoClient, BadBlocks,
 };
 use client::bad_blocks;
-use engines::{EthEngine, EpochTransition, ForkChoice, EngineError};
+use engines::{MAX_UNCLE_AGE, EthEngine, EpochTransition, ForkChoice, EngineError};
 use engines::epoch::PendingTransition;
 use error::{
 	ImportErrorKind, ExecutionError, CallError, BlockError,
@@ -1918,7 +1918,7 @@ impl BlockChainClient for Client {
 	}
 
 	fn find_uncles(&self, hash: &H256) -> Option<Vec<H256>> {
-		self.chain.read().find_uncle_hashes(hash, self.engine.maximum_uncle_age())
+		self.chain.read().find_uncle_hashes(hash, MAX_UNCLE_AGE)
 	}
 
 	fn state_data(&self, hash: &H256) -> Option<Bytes> {
@@ -2282,7 +2282,7 @@ impl ReopenBlock for Client {
 			let h = chain.best_block_hash();
 			// Add new uncles
 			let uncles = chain
-				.find_uncle_hashes(&h, engine.maximum_uncle_age())
+				.find_uncle_hashes(&h, MAX_UNCLE_AGE)
 				.unwrap_or_else(Vec::new);
 
 			for h in uncles {
@@ -2326,7 +2326,7 @@ impl PrepareOpenBlock for Client {
 
 		// Add uncles
 		chain
-			.find_uncle_headers(&h, engine.maximum_uncle_age())
+			.find_uncle_headers(&h, MAX_UNCLE_AGE)
 			.unwrap_or_else(Vec::new)
 			.into_iter()
 			.take(engine.maximum_uncle_count(open_block.header().number()))
diff --git a/ethcore/src/engines/mod.rs b/ethcore/src/engines/mod.rs
index 5d83bf0a3..06e6b522b 100644
--- a/ethcore/src/engines/mod.rs
+++ b/ethcore/src/engines/mod.rs
@@ -59,6 +59,8 @@ use block::ExecutedBlock;
 /// Default EIP-210 contract code.
 /// As defined in https://github.com/ethereum/EIPs/pull/210
 pub const DEFAULT_BLOCKHASH_CONTRACT: &'static str = "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";
+/// The number of generations back that uncles can be.
+pub const MAX_UNCLE_AGE: usize = 6;
 
 /// Voting errors.
 #[derive(Debug)]
@@ -242,9 +244,6 @@ pub trait Engine<M: Machine>: Sync + Send {
 	/// Maximum number of uncles a block is allowed to declare.
 	fn maximum_uncle_count(&self, _block: BlockNumber) -> usize { 0 }
 
-	/// The number of generations back that uncles can be.
-	fn maximum_uncle_age(&self) -> usize { 6 }
-
 	/// Optional maximum gas limit.
 	fn maximum_gas_limit(&self) -> Option<U256> { None }
 
diff --git a/ethcore/src/verification/verification.rs b/ethcore/src/verification/verification.rs
index 2ce9f9de3..8a11f0ef4 100644
--- a/ethcore/src/verification/verification.rs
+++ b/ethcore/src/verification/verification.rs
@@ -34,7 +34,7 @@ use unexpected::{Mismatch, OutOfBounds};
 use blockchain::*;
 use call_contract::CallContract;
 use client::BlockInfo;
-use engines::EthEngine;
+use engines::{EthEngine, MAX_UNCLE_AGE};
 use error::{BlockError, Error};
 use types::{BlockNumber, header::Header};
 use types::transaction::SignedTransaction;
@@ -192,7 +192,7 @@ fn verify_uncles(block: &PreverifiedBlock, bc: &BlockProvider, engine: &EthEngin
 		excluded.insert(header.hash());
 		let mut hash = header.parent_hash().clone();
 		excluded.insert(hash.clone());
-		for _ in 0..engine.maximum_uncle_age() {
+		for _ in 0..MAX_UNCLE_AGE {
 			match bc.block_details(&hash) {
 				Some(details) => {
 					excluded.insert(details.parent);
@@ -225,7 +225,7 @@ fn verify_uncles(block: &PreverifiedBlock, bc: &BlockProvider, engine: &EthEngin
 			//												(8 Invalid)
 
 			let depth = if header.number() > uncle.number() { header.number() - uncle.number() } else { 0 };
-			if depth > engine.maximum_uncle_age() as u64 {
+			if depth > MAX_UNCLE_AGE as u64 {
 				return Err(From::from(BlockError::UncleTooOld(OutOfBounds { min: Some(header.number() - depth), max: Some(header.number() - 1), found: uncle.number() })));
 			}
 			else if depth < 1 {