diff --git a/ethcore/res/instant_seal.json b/ethcore/res/instant_seal.json
index b7c29a01f..2d5b38659 100644
--- a/ethcore/res/instant_seal.json
+++ b/ethcore/res/instant_seal.json
@@ -1,5 +1,5 @@
 {
-	"name": "TestInstantSeal",
+	"name": "DevelopmentChain",
 	"engine": {
 		"InstantSeal": null
 	},
@@ -28,6 +28,6 @@
 		"0000000000000000000000000000000000000002": { "balance": "1", "nonce": "1048576", "builtin": { "name": "sha256", "pricing": { "linear": { "base": 60, "word": 12 } } } },
 		"0000000000000000000000000000000000000003": { "balance": "1", "nonce": "1048576", "builtin": { "name": "ripemd160", "pricing": { "linear": { "base": 600, "word": 120 } } } },
 		"0000000000000000000000000000000000000004": { "balance": "1", "nonce": "1048576", "builtin": { "name": "identity", "pricing": { "linear": { "base": 15, "word": 3 } } } },
-		"102e61f5d8f9bc71d0ad4a084df4e65e05ce0e1c": { "balance": "1606938044258990275541962092341162602522202993782792835301376", "nonce": "1048576" }
+		"0x00a329c0648769a73afac7f9381e08fb43dbea72": { "balance": "1606938044258990275541962092341162602522202993782792835301376", "nonce": "1048576" }
 	}
 }
diff --git a/ethcore/src/engines/instant_seal.rs b/ethcore/src/engines/instant_seal.rs
index acead19b4..75fae4d81 100644
--- a/ethcore/src/engines/instant_seal.rs
+++ b/ethcore/src/engines/instant_seal.rs
@@ -55,7 +55,7 @@ impl Engine for InstantSeal {
 	}
 
 	fn schedule(&self, _env_info: &EnvInfo) -> Schedule {
-		Schedule::new_homestead()
+		Schedule::new_post_eip150(false, false, false)
 	}
 
 	fn is_sealer(&self, _author: &Address) -> Option<bool> { Some(true) }
@@ -79,7 +79,7 @@ mod tests {
 		let tap = AccountProvider::transient_provider();
 		let addr = tap.insert_account("".sha3(), "").unwrap();
 
-		let spec = Spec::new_test_instant();
+		let spec = Spec::new_instant();
 		let engine = &*spec.engine;
 		let genesis_header = spec.genesis_header();
 		let mut db_result = get_temp_state_db();
@@ -95,7 +95,7 @@ mod tests {
 
 	#[test]
 	fn instant_cant_verify() {
-		let engine = Spec::new_test_instant().engine;
+		let engine = Spec::new_instant().engine;
 		let mut header: Header = Header::default();
 
 		assert!(engine.verify_block_basic(&header, None).is_ok());
diff --git a/ethcore/src/miner/miner.rs b/ethcore/src/miner/miner.rs
index 19a2b9a10..af4677cf3 100644
--- a/ethcore/src/miner/miner.rs
+++ b/ethcore/src/miner/miner.rs
@@ -1251,7 +1251,7 @@ mod tests {
 
 	#[test]
 	fn internal_seals_without_work() {
-		let miner = Miner::with_spec(&Spec::new_test_instant());
+		let miner = Miner::with_spec(&Spec::new_instant());
 
 		let c = generate_dummy_client(2);
 		let client = c.reference().as_ref();
diff --git a/ethcore/src/spec/spec.rs b/ethcore/src/spec/spec.rs
index 6bfb1bcc1..de1b7db42 100644
--- a/ethcore/src/spec/spec.rs
+++ b/ethcore/src/spec/spec.rs
@@ -135,6 +135,12 @@ impl From<ethjson::spec::Spec> for Spec {
 	}
 }
 
+macro_rules! load_bundled {
+	($e:expr) => {
+		Spec::load(include_bytes!(concat!("../../res/", $e, ".json")) as &[u8]).expect(concat!("Chain spec ", $e, " is invalid."))
+	};
+}
+
 impl Spec {
 	/// Convert engine spec into a arc'd Engine of the right underlying type.
 	/// TODO avoid this hard-coded nastiness - use dynamic-linked plugin framework instead.
@@ -267,19 +273,13 @@ impl Spec {
 	}
 
 	/// Create a new Spec which conforms to the Frontier-era Morden chain except that it's a NullEngine consensus.
-	pub fn new_test() -> Self {
-		Spec::load(include_bytes!("../../res/null_morden.json") as &[u8]).expect("null_morden.json is invalid")
-	}
+	pub fn new_test() -> Spec { load_bundled!("null_morden") }
 
 	/// Create a new Spec which is a NullEngine consensus with a premine of address whose secret is sha3('').
-	pub fn new_null() -> Self {
-		Spec::load(include_bytes!("../../res/null.json") as &[u8]).expect("null.json is invalid")
-	}
+	pub fn new_null() -> Spec { load_bundled!("null") }
 
 	/// Create a new Spec with InstantSeal consensus which does internal sealing (not requiring work).
-	pub fn new_test_instant() -> Self {
-		Spec::load(include_bytes!("../../res/instant_seal.json") as &[u8]).expect("instant_seal.json is invalid")
-	}
+	pub fn new_instant() -> Spec { load_bundled!("instant_seal") }
 }
 
 #[cfg(test)]
diff --git a/parity/cli/usage.txt b/parity/cli/usage.txt
index ba27c4902..89603d311 100644
--- a/parity/cli/usage.txt
+++ b/parity/cli/usage.txt
@@ -32,8 +32,8 @@ Operating Options:
                            (default: {flag_mode_alarm}).
   --chain CHAIN            Specify the blockchain type. CHAIN may be either a
                            JSON chain specification file or olympic, frontier,
-                           homestead, mainnet, morden, classic, expanse or
-                           testnet (default: {flag_chain}).
+                           homestead, mainnet, morden, classic, expanse,
+                           testnet or dev (default: {flag_chain}).
   -d --db-path PATH        Specify the database & configuration directory path
                            (default: {flag_db_path}).
   --keys-path PATH         Specify the path for JSON key files to be found
diff --git a/parity/params.rs b/parity/params.rs
index 5a81fba7f..54e08da32 100644
--- a/parity/params.rs
+++ b/parity/params.rs
@@ -31,6 +31,7 @@ pub enum SpecType {
 	Olympic,
 	Classic,
 	Expanse,
+	Dev,
 	Custom(String),
 }
 
@@ -50,6 +51,7 @@ impl str::FromStr for SpecType {
 			"morden" | "testnet" => SpecType::Testnet,
 			"olympic" => SpecType::Olympic,
 			"expanse" => SpecType::Expanse,
+			"dev" => SpecType::Dev,
 			other => SpecType::Custom(other.into()),
 		};
 		Ok(spec)
@@ -64,6 +66,7 @@ impl SpecType {
 			SpecType::Olympic => Ok(ethereum::new_olympic()),
 			SpecType::Classic => Ok(ethereum::new_classic()),
 			SpecType::Expanse => Ok(ethereum::new_expanse()),
+			SpecType::Dev => Ok(Spec::new_instant()),
 			SpecType::Custom(ref filename) => {
 				let file = try!(fs::File::open(filename).map_err(|_| "Could not load specification file."));
 				Spec::load(file)