diff --git a/ethcore/src/tests/chain.rs b/ethcore/src/json_tests/chain.rs
similarity index 99%
rename from ethcore/src/tests/chain.rs
rename to ethcore/src/json_tests/chain.rs
index 4d1835033..19e792f52 100644
--- a/ethcore/src/tests/chain.rs
+++ b/ethcore/src/json_tests/chain.rs
@@ -3,7 +3,7 @@ use client::{BlockChainClient,Client};
 use pod_state::*;
 use block::Block;
 use ethereum;
-use super::helpers::*;
+use tests::helpers::*;
 
 pub fn json_chain_test(json_data: &[u8], era: ChainEra) -> Vec<String> {
 	init_log();
diff --git a/ethcore/src/tests/client.rs b/ethcore/src/json_tests/client.rs
similarity index 98%
rename from ethcore/src/tests/client.rs
rename to ethcore/src/json_tests/client.rs
index 56b6e7db0..1d09ed079 100644
--- a/ethcore/src/tests/client.rs
+++ b/ethcore/src/json_tests/client.rs
@@ -1,6 +1,6 @@
 use client::{BlockChainClient,Client};
 use super::test_common::*;
-use super::helpers::*;
+use tests::helpers::*;
 
 #[test]
 fn created() {
@@ -75,4 +75,4 @@ fn can_collect_garbage() {
 	let client = client_result.reference();
 	client.tick();
 	assert!(client.cache_info().blocks < 100 * 1024);
-}
\ No newline at end of file
+}
diff --git a/ethcore/src/tests/executive.rs b/ethcore/src/json_tests/executive.rs
similarity index 100%
rename from ethcore/src/tests/executive.rs
rename to ethcore/src/json_tests/executive.rs
diff --git a/ethcore/src/tests/homestead_chain.rs b/ethcore/src/json_tests/homestead_chain.rs
similarity index 98%
rename from ethcore/src/tests/homestead_chain.rs
rename to ethcore/src/json_tests/homestead_chain.rs
index 5691f3a19..1962da1bc 100644
--- a/ethcore/src/tests/homestead_chain.rs
+++ b/ethcore/src/json_tests/homestead_chain.rs
@@ -1,6 +1,6 @@
 use super::test_common::*;
-use super::helpers::*;
 use super::chain::json_chain_test;
+use tests::helpers::*;
 
 fn do_json_test(json_data: &[u8]) -> Vec<String> {
 	json_chain_test(json_data, ChainEra::Homestead)
diff --git a/ethcore/src/tests/homestead_state.rs b/ethcore/src/json_tests/homestead_state.rs
similarity index 98%
rename from ethcore/src/tests/homestead_state.rs
rename to ethcore/src/json_tests/homestead_state.rs
index f0f7cd21e..474d56f8a 100644
--- a/ethcore/src/tests/homestead_state.rs
+++ b/ethcore/src/json_tests/homestead_state.rs
@@ -1,5 +1,5 @@
 use super::test_common::*;
-use super::helpers::*;
+use tests::helpers::*;
 use super::state::json_chain_test;
 
 fn do_json_test(json_data: &[u8]) -> Vec<String> {
diff --git a/ethcore/src/json_tests/mod.rs b/ethcore/src/json_tests/mod.rs
new file mode 100644
index 000000000..b5d6779bc
--- /dev/null
+++ b/ethcore/src/json_tests/mod.rs
@@ -0,0 +1,10 @@
+#[macro_use]
+mod test_common;
+
+mod transaction;
+mod executive;
+mod state;
+mod client;
+mod chain;
+mod homestead_state;
+mod homestead_chain;
diff --git a/ethcore/src/tests/state.rs b/ethcore/src/json_tests/state.rs
similarity index 99%
rename from ethcore/src/tests/state.rs
rename to ethcore/src/json_tests/state.rs
index 34b24de3b..3fb43c132 100644
--- a/ethcore/src/tests/state.rs
+++ b/ethcore/src/json_tests/state.rs
@@ -1,5 +1,5 @@
 use super::test_common::*;
-use super::helpers::*;
+use tests::helpers::*;
 use pod_state::*;
 use state_diff::*;
 use ethereum;
diff --git a/ethcore/src/tests/test_common.rs b/ethcore/src/json_tests/test_common.rs
similarity index 86%
rename from ethcore/src/tests/test_common.rs
rename to ethcore/src/json_tests/test_common.rs
index fd88ae96a..87e7b979e 100644
--- a/ethcore/src/tests/test_common.rs
+++ b/ethcore/src/json_tests/test_common.rs
@@ -12,7 +12,6 @@ macro_rules! declare_test {
 		#[ignore]
 		#[test]
 		#[allow(non_snake_case)]
-		#[cfg(feature="json-tests")]
 		fn $id() {
 			test!($name);
 		}
@@ -21,7 +20,6 @@ macro_rules! declare_test {
 		#[cfg(feature = "test-heavy")]
 		#[test]
 		#[allow(non_snake_case)]
-		#[cfg(feature="json-tests")]
 		fn $id() {
 			test!($name);
 		}
@@ -29,7 +27,6 @@ macro_rules! declare_test {
 	($id: ident, $name: expr) => {
 		#[test]
 		#[allow(non_snake_case)]
-		#[cfg(feature="json-tests")]
 		fn $id() {
 			test!($name);
 		}
diff --git a/ethcore/src/tests/transaction.rs b/ethcore/src/json_tests/transaction.rs
similarity index 100%
rename from ethcore/src/tests/transaction.rs
rename to ethcore/src/json_tests/transaction.rs
diff --git a/ethcore/src/lib.rs b/ethcore/src/lib.rs
index 32792fe34..66da6c274 100644
--- a/ethcore/src/lib.rs
+++ b/ethcore/src/lib.rs
@@ -108,4 +108,8 @@ mod executive;
 mod externalities;
 mod verification;
 
-#[cfg(test)] mod tests;
+#[cfg(test)] 
+mod tests;
+#[cfg(test)]
+#[cfg(feature="json-tests")] 
+mod json_tests;
diff --git a/ethcore/src/tests/helpers.rs b/ethcore/src/tests/helpers.rs
index 1923e9164..ddc2aedc2 100644
--- a/ethcore/src/tests/helpers.rs
+++ b/ethcore/src/tests/helpers.rs
@@ -1,6 +1,6 @@
 use client::{BlockChainClient,Client};
 use std::env;
-use super::test_common::*;
+use common::*;
 use std::path::PathBuf;
 use spec::*;
 use std::fs::{remove_dir_all};
diff --git a/ethcore/src/tests/mod.rs b/ethcore/src/tests/mod.rs
index bda581eac..1630fabcd 100644
--- a/ethcore/src/tests/mod.rs
+++ b/ethcore/src/tests/mod.rs
@@ -1,11 +1 @@
-#[macro_use]
-mod test_common;
-
-mod transaction;
-mod executive;
-mod state;
-mod client;
-mod chain;
 pub mod helpers;
-mod homestead_state;
-mod homestead_chain;
\ No newline at end of file
diff --git a/ethcore/src/transaction.rs b/ethcore/src/transaction.rs
index 61c17a755..7f681bcac 100644
--- a/ethcore/src/transaction.rs
+++ b/ethcore/src/transaction.rs
@@ -64,6 +64,7 @@ impl Transaction {
 			sender: RefCell::new(None),
 		}
 	}
+
 	/// Create a new message-call transaction.
 	pub fn new_call(to: Address, value: U256, data: Bytes, gas: U256, gas_price: U256, nonce: U256) -> Transaction {
 		Transaction {