diff --git a/json/src/spec/ethash.rs b/json/src/spec/ethash.rs
index 16d05a18f..926dcacee 100644
--- a/json/src/spec/ethash.rs
+++ b/json/src/spec/ethash.rs
@@ -131,7 +131,11 @@ pub struct Ethash {
 #[cfg(test)]
 mod tests {
 	use serde_json;
-	use spec::ethash::Ethash;
+	use uint::Uint;
+	use util::U256;
+	use hash::Address;
+	use util::hash::H160;
+	use spec::ethash::{Ethash, EthashParams};
 
 	#[test]
 	fn ethash_deserialization() {
@@ -170,17 +174,71 @@ mod tests {
 				],
 				"difficultyHardforkTransition": "0x59d9",
 				"difficultyHardforkBoundDivisor": "0x0200",
-				"bombDefuseTransition": "0x42",
+				"bombDefuseTransition": "0x41",
 				"eip100bTransition": "0x42",
-				"eip150Transition": "0x42",
-				"eip155Transition": "0x42",
-				"eip160Transition": "0x42",
-				"eip161abcTransition": "0x42",
-				"eip161dTransition": "0x42"
+				"eip150Transition": "0x43",
+				"eip155Transition": "0x44",
+				"eip160Transition": "0x45",
+				"eip161abcTransition": "0x46",
+				"eip161dTransition": "0x47"
 			}
 		}"#;
 
-		let _deserialized: Ethash = serde_json::from_str(s).unwrap();
+		let deserialized: Ethash = serde_json::from_str(s).unwrap();
+
+		assert_eq!(deserialized, Ethash{
+			params: EthashParams{
+				gas_limit_bound_divisor: Uint(U256::from(0x0400)),
+				minimum_difficulty: Uint(U256::from(0x020000)),
+				difficulty_bound_divisor: Uint(U256::from(0x0800)),
+				difficulty_increment_divisor: None,
+				metropolis_difficulty_increment_divisor: None,
+				duration_limit: Uint(U256::from(0x0d)),
+				block_reward: Uint(U256::from(0x4563918244F40000u64)),
+				registrar: Some(Address(H160::from("0xc6d9d2cd449a754c494264e1809c50e34d64562b"))),
+				homestead_transition: Some(Uint(U256::from(0x42))),
+				dao_hardfork_transition: Some(Uint(U256::from(0x08))),
+				dao_hardfork_beneficiary: Some(Address(H160::from("0xabcabcabcabcabcabcabcabcabcabcabcabcabca"))),
+				dao_hardfork_accounts: Some(vec![
+					Address(H160::from("0x304a554a310c7e546dfe434669c62820b7d83490")),
+					Address(H160::from("0x914d1b8b43e92723e64fd0a06f5bdb8dd9b10c79")),
+					Address(H160::from("0xfe24cdd8648121a43a7c86d289be4dd2951ed49f")),
+					Address(H160::from("0x17802f43a0137c506ba92291391a8a8f207f487d")),
+					Address(H160::from("0xb136707642a4ea12fb4bae820f03d2562ebff487")),
+					Address(H160::from("0xdbe9b615a3ae8709af8b93336ce9b477e4ac0940")),
+					Address(H160::from("0xf14c14075d6c4ed84b86798af0956deef67365b5")),
+					Address(H160::from("0xca544e5c4687d109611d0f8f928b53a25af72448")),
+					Address(H160::from("0xaeeb8ff27288bdabc0fa5ebb731b6f409507516c")),
+					Address(H160::from("0xcbb9d3703e651b0d496cdefb8b92c25aeb2171f7")),
+					Address(H160::from("0xaccc230e8a6e5be9160b8cdf2864dd2a001c28b6")),
+					Address(H160::from("0x2b3455ec7fedf16e646268bf88846bd7a2319bb2")),
+					Address(H160::from("0x4613f3bca5c44ea06337a9e439fbc6d42e501d0a")),
+					Address(H160::from("0xd343b217de44030afaa275f54d31a9317c7f441e")),
+					Address(H160::from("0x84ef4b2357079cd7a7c69fd7a37cd0609a679106")),
+					Address(H160::from("0xda2fef9e4a3230988ff17df2165440f37e8b1708")),
+					Address(H160::from("0xf4c64518ea10f995918a454158c6b61407ea345c")),
+					Address(H160::from("0x7602b46df5390e432ef1c307d4f2c9ff6d65cc97")),
+					Address(H160::from("0xbb9bc244d798123fde783fcc1c72d3bb8c189413")),
+					Address(H160::from("0x807640a13483f8ac783c557fcdf27be11ea4ac7a")),
+				]),
+				difficulty_hardfork_transition: Some(Uint(U256::from(0x59d9))),
+				difficulty_hardfork_bound_divisor: Some(Uint(U256::from(0x0200))),
+				bomb_defuse_transition: Some(Uint(U256::from(0x41))),
+				eip100b_transition: Some(Uint(U256::from(0x42))),
+				eip150_transition: Some(Uint(U256::from(0x43))),
+				eip155_transition: Some(Uint(U256::from(0x44))),
+				eip160_transition: Some(Uint(U256::from(0x45))),
+				eip161abc_transition: Some(Uint(U256::from(0x46))),
+				eip161d_transition: Some(Uint(U256::from(0x47))),
+				ecip1010_pause_transition: None,
+				ecip1010_continue_transition: None,
+				max_code_size: None,
+				max_gas_limit_transition: None,
+				max_gas_limit: None,
+				min_gas_price_transition: None,
+				min_gas_price: None,
+			}
+		});
 	}
 
 	#[test]
@@ -195,6 +253,38 @@ mod tests {
 			}
 		}"#;
 
-		let _deserialized: Ethash = serde_json::from_str(s).unwrap();
+		let deserialized: Ethash = serde_json::from_str(s).unwrap();
+		assert_eq!(deserialized, Ethash{
+			params: EthashParams{
+				gas_limit_bound_divisor: Uint(U256::from(0x0400)),
+				minimum_difficulty: Uint(U256::from(0x020000)),
+				difficulty_bound_divisor: Uint(U256::from(0x0800)),
+				difficulty_increment_divisor: None,
+				metropolis_difficulty_increment_divisor: None,
+				duration_limit: Uint(U256::from(0x0d)),
+				block_reward: Uint(U256::from(0x4563918244F40000u64)),
+				registrar: None,
+				homestead_transition: None,
+				dao_hardfork_transition: None,
+				dao_hardfork_beneficiary: None,
+				dao_hardfork_accounts: None,
+				difficulty_hardfork_transition: None,
+				difficulty_hardfork_bound_divisor: None,
+				bomb_defuse_transition: None,
+				eip100b_transition: None,
+				eip150_transition: None,
+				eip155_transition: None,
+				eip160_transition: None,
+				eip161abc_transition: None,
+				eip161d_transition: None,
+				ecip1010_pause_transition: None,
+				ecip1010_continue_transition: None,
+				max_code_size: None,
+				max_gas_limit_transition: None,
+				max_gas_limit: None,
+				min_gas_price_transition: None,
+				min_gas_price: None,
+			}
+		});
 	}
 }