diff --git a/ethcore/src/ethereum/ethash.rs b/ethcore/src/ethereum/ethash.rs
index f49725ab3..7d99a456a 100644
--- a/ethcore/src/ethereum/ethash.rs
+++ b/ethcore/src/ethereum/ethash.rs
@@ -262,10 +262,7 @@ mod tests {
 
 	use common::*;
 	use block::*;
-	use spec::*;
 	use engine::*;
-	use evm::Schedule;
-	use evm::Factory;
 	use tests::helpers::*;
 	use super::*;
 	use super::super::new_morden;
@@ -319,7 +316,7 @@ mod tests {
 	#[test]
 	fn can_return_factory() {
 		let engine = Ethash::new_test(new_morden());
-		let factory = engine.vm_factory();
+		engine.vm_factory();
 	}
 
 	#[test]
@@ -359,7 +356,7 @@ mod tests {
 
 		match verify_result {
 			Err(Error::Block(BlockError::InvalidSealArity(_))) => {},
-			_ => { panic!("should be block difficulty error"); }
+			_ => { panic!("should be block seal mismatch error"); }
 		}
 	}
 
@@ -377,6 +374,22 @@ mod tests {
 		}
 	}
 
+	#[test]
+	fn can_do_proof_of_work_verification_fail() {
+		let engine = Ethash::new_test(new_morden());
+		let mut header: Header = Header::default();
+		header.set_seal(vec![rlp::encode(&H256::zero()).to_vec(), rlp::encode(&H64::zero()).to_vec()]);
+		header.set_difficulty(U256::from_str("ffffffffffffffffffffffffffffffffffffffffffffaaaaaaaaaaaaaaaaaaaa").unwrap());
+
+		let verify_result = engine.verify_block_basic(&header, None);
+
+		match verify_result {
+			Err(Error::Block(BlockError::InvalidProofOfWork(_))) => {},
+			_ => { panic!("should be invalid proof of work error"); }
+		}
+
+	}
+
 	// TODO: difficulty test
 }
 
diff --git a/ethcore/src/evm/factory.rs b/ethcore/src/evm/factory.rs
index f1be0e427..4a9bd38ba 100644
--- a/ethcore/src/evm/factory.rs
+++ b/ethcore/src/evm/factory.rs
@@ -159,11 +159,13 @@ macro_rules! evm_test_ignore(
 		#[test]
 		#[ignore]
 		#[cfg(feature = "jit")]
+		#[cfg(feature = "ignored-tests")]
 		fn $name_jit() {
 			$name_test(Factory::new(VMType::Jit));
 		}
 		#[test]
 		#[ignore]
+		#[cfg(feature = "ignored-tests")]
 		fn $name_int() {
 			$name_test(Factory::new(VMType::Interpreter));
 		}
diff --git a/ethcore/src/executive.rs b/ethcore/src/executive.rs
index 2d6039953..812dc3acd 100644
--- a/ethcore/src/executive.rs
+++ b/ethcore/src/executive.rs
@@ -360,6 +360,7 @@ impl<'a> Executive<'a> {
 }
 
 #[cfg(test)]
+#[allow(dead_code)]
 mod tests {
 	use super::*;
 	use common::*;
@@ -599,6 +600,7 @@ mod tests {
 	}
 
 	// test is incorrect, mk
+	// TODO: fix (preferred) or remove
 	evm_test_ignore!{test_aba_calls: test_aba_calls_jit, test_aba_calls_int}
 	fn test_aba_calls(factory: Factory) {
 		// 60 00 - push 0
@@ -659,6 +661,7 @@ mod tests {
 	}
 
 	// test is incorrect, mk
+	// TODO: fix (preferred) or remove
 	evm_test_ignore!{test_recursive_bomb1: test_recursive_bomb1_jit, test_recursive_bomb1_int}
 	fn test_recursive_bomb1(factory: Factory) {
 		// 60 01 - push 1
@@ -704,6 +707,7 @@ mod tests {
 	}
 
 	// test is incorrect, mk
+	// TODO: fix (preferred) or remove
 	evm_test_ignore!{test_transact_simple: test_transact_simple_jit, test_transact_simple_int}
 	fn test_transact_simple(factory: Factory) {
 		let keypair = KeyPair::create().unwrap();
@@ -902,5 +906,4 @@ mod tests {
 			}
 		}
 	}
-
 }
diff --git a/ethcore/src/json_tests/mod.rs b/ethcore/src/json_tests/mod.rs
index 1cae0fa1d..df67de76d 100644
--- a/ethcore/src/json_tests/mod.rs
+++ b/ethcore/src/json_tests/mod.rs
@@ -20,7 +20,6 @@ mod test_common;
 mod transaction;
 mod executive;
 mod state;
-mod client;
 mod chain;
 mod homestead_state;
 mod homestead_chain;
diff --git a/ethcore/src/json_tests/client.rs b/ethcore/src/tests/client.rs
similarity index 99%
rename from ethcore/src/json_tests/client.rs
rename to ethcore/src/tests/client.rs
index 2d3166c74..697647187 100644
--- a/ethcore/src/json_tests/client.rs
+++ b/ethcore/src/tests/client.rs
@@ -15,8 +15,8 @@
 // along with Parity.  If not, see <http://www.gnu.org/licenses/>.
 
 use client::{BlockChainClient,Client};
-use super::test_common::*;
 use tests::helpers::*;
+use common::*;
 
 #[test]
 fn created() {
diff --git a/ethcore/src/tests/helpers.rs b/ethcore/src/tests/helpers.rs
index 9ec36fa93..f5815b718 100644
--- a/ethcore/src/tests/helpers.rs
+++ b/ethcore/src/tests/helpers.rs
@@ -14,7 +14,6 @@
 // You should have received a copy of the GNU General Public License
 // along with Parity.  If not, see <http://www.gnu.org/licenses/>.
 
-#[cfg(feature = "json-tests")]
 use client::{BlockChainClient, Client};
 use std::env;
 use common::*;
@@ -134,7 +133,6 @@ pub fn create_test_block_with_data(header: &Header, transactions: &[&SignedTrans
 	rlp.out()
 }
 
-#[cfg(feature = "json-tests")]
 pub fn generate_dummy_client(block_number: u32) -> GuardedTempResult<Arc<Client>> {
 	let dir = RandomTempPath::new();
 
@@ -174,7 +172,6 @@ pub fn generate_dummy_client(block_number: u32) -> GuardedTempResult<Arc<Client>
 	}
 }
 
-#[cfg(feature = "json-tests")]
 pub fn get_test_client_with_blocks(blocks: Vec<Bytes>) -> GuardedTempResult<Arc<Client>> {
 	let dir = RandomTempPath::new();
 	let client = Client::new(get_test_spec(), dir.as_path(), IoChannel::disconnected()).unwrap();
@@ -271,7 +268,6 @@ pub fn get_good_dummy_block() -> Bytes {
 	create_test_block(&block_header)
 }
 
-#[cfg(feature = "json-tests")]
 pub fn get_bad_state_dummy_block() -> Bytes {
 	let mut block_header = Header::new();
 	let test_spec = get_test_spec();
diff --git a/ethcore/src/tests/mod.rs b/ethcore/src/tests/mod.rs
index a4e13730a..28c1b3b5b 100644
--- a/ethcore/src/tests/mod.rs
+++ b/ethcore/src/tests/mod.rs
@@ -15,3 +15,4 @@
 // along with Parity.  If not, see <http://www.gnu.org/licenses/>.
 
 pub mod helpers;
+mod client;
\ No newline at end of file