diff --git a/Cargo.lock b/Cargo.lock
index 18d4177b6..ba04e2184 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -27,7 +27,7 @@ dependencies = [
  "fdlimit 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "hyper 0.9.14 (registry+https://github.com/rust-lang/crates.io-index)",
  "isatty 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "jsonrpc-core 5.1.0 (git+https://github.com/ethcore/jsonrpc.git)",
+ "jsonrpc-core 6.0.0 (git+https://github.com/ethcore/jsonrpc.git)",
  "lazy_static 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "num_cpus 0.2.11 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -428,8 +428,8 @@ dependencies = [
  "fetch 0.1.0",
  "futures 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "hyper 0.10.0-a.0 (git+https://github.com/ethcore/hyper)",
- "jsonrpc-core 5.1.0 (git+https://github.com/ethcore/jsonrpc.git)",
- "jsonrpc-http-server 7.0.0 (git+https://github.com/ethcore/jsonrpc.git)",
+ "jsonrpc-core 6.0.0 (git+https://github.com/ethcore/jsonrpc.git)",
+ "jsonrpc-http-server 6.0.0 (git+https://github.com/ethcore/jsonrpc.git)",
  "linked-hash-map 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "mime 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -601,10 +601,10 @@ dependencies = [
  "ethsync 1.6.0",
  "fetch 0.1.0",
  "futures 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
- "jsonrpc-core 5.1.0 (git+https://github.com/ethcore/jsonrpc.git)",
- "jsonrpc-http-server 7.0.0 (git+https://github.com/ethcore/jsonrpc.git)",
- "jsonrpc-ipc-server 1.0.0 (git+https://github.com/ethcore/jsonrpc.git)",
- "jsonrpc-macros 0.2.0 (git+https://github.com/ethcore/jsonrpc.git)",
+ "jsonrpc-core 6.0.0 (git+https://github.com/ethcore/jsonrpc.git)",
+ "jsonrpc-http-server 6.0.0 (git+https://github.com/ethcore/jsonrpc.git)",
+ "jsonrpc-ipc-server 6.0.0 (git+https://github.com/ethcore/jsonrpc.git)",
+ "jsonrpc-macros 6.0.0 (git+https://github.com/ethcore/jsonrpc.git)",
  "log 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "order-stat 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "parity-reactor 0.1.0",
@@ -629,7 +629,7 @@ dependencies = [
  "ethcore-io 1.6.0",
  "ethcore-rpc 1.6.0",
  "ethcore-util 1.6.0",
- "jsonrpc-core 5.1.0 (git+https://github.com/ethcore/jsonrpc.git)",
+ "jsonrpc-core 6.0.0 (git+https://github.com/ethcore/jsonrpc.git)",
  "log 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "parity-dapps-glue 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "parity-ui 1.6.0",
@@ -649,9 +649,9 @@ dependencies = [
  "ethcore-ipc-nano 1.6.0",
  "ethcore-util 1.6.0",
  "futures 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
- "jsonrpc-core 5.1.0 (git+https://github.com/ethcore/jsonrpc.git)",
- "jsonrpc-macros 0.2.0 (git+https://github.com/ethcore/jsonrpc.git)",
- "jsonrpc-tcp-server 1.0.0 (git+https://github.com/ethcore/jsonrpc.git)",
+ "jsonrpc-core 6.0.0 (git+https://github.com/ethcore/jsonrpc.git)",
+ "jsonrpc-macros 6.0.0 (git+https://github.com/ethcore/jsonrpc.git)",
+ "jsonrpc-tcp-server 6.0.0 (git+https://github.com/ethcore/jsonrpc.git)",
  "lazy_static 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "mio 0.5.1 (git+https://github.com/ethcore/mio?branch=v0.5.x)",
@@ -1030,8 +1030,8 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "jsonrpc-core"
-version = "5.1.0"
-source = "git+https://github.com/ethcore/jsonrpc.git#cac47f72090c3db78e83d56d333ada52a22dd3a9"
+version = "6.0.0"
+source = "git+https://github.com/ethcore/jsonrpc.git#86d7a89c85f324b5f6671315d9b71010ca995300"
 dependencies = [
  "futures 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1043,11 +1043,11 @@ dependencies = [
 
 [[package]]
 name = "jsonrpc-http-server"
-version = "7.0.0"
-source = "git+https://github.com/ethcore/jsonrpc.git#cac47f72090c3db78e83d56d333ada52a22dd3a9"
+version = "6.0.0"
+source = "git+https://github.com/ethcore/jsonrpc.git#86d7a89c85f324b5f6671315d9b71010ca995300"
 dependencies = [
  "hyper 0.10.0-a.0 (git+https://github.com/ethcore/hyper)",
- "jsonrpc-core 5.1.0 (git+https://github.com/ethcore/jsonrpc.git)",
+ "jsonrpc-core 6.0.0 (git+https://github.com/ethcore/jsonrpc.git)",
  "log 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "tokio-core 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "unicase 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1055,12 +1055,12 @@ dependencies = [
 
 [[package]]
 name = "jsonrpc-ipc-server"
-version = "1.0.0"
-source = "git+https://github.com/ethcore/jsonrpc.git#cac47f72090c3db78e83d56d333ada52a22dd3a9"
+version = "6.0.0"
+source = "git+https://github.com/ethcore/jsonrpc.git#86d7a89c85f324b5f6671315d9b71010ca995300"
 dependencies = [
  "bytes 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "env_logger 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
- "jsonrpc-core 5.1.0 (git+https://github.com/ethcore/jsonrpc.git)",
+ "jsonrpc-core 6.0.0 (git+https://github.com/ethcore/jsonrpc.git)",
  "lazy_static 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "mio 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1071,20 +1071,20 @@ dependencies = [
 
 [[package]]
 name = "jsonrpc-macros"
-version = "0.2.0"
-source = "git+https://github.com/ethcore/jsonrpc.git#cac47f72090c3db78e83d56d333ada52a22dd3a9"
+version = "6.0.0"
+source = "git+https://github.com/ethcore/jsonrpc.git#86d7a89c85f324b5f6671315d9b71010ca995300"
 dependencies = [
- "jsonrpc-core 5.1.0 (git+https://github.com/ethcore/jsonrpc.git)",
+ "jsonrpc-core 6.0.0 (git+https://github.com/ethcore/jsonrpc.git)",
  "serde 0.9.6 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "jsonrpc-tcp-server"
-version = "1.0.0"
-source = "git+https://github.com/ethcore/jsonrpc.git#cac47f72090c3db78e83d56d333ada52a22dd3a9"
+version = "6.0.0"
+source = "git+https://github.com/ethcore/jsonrpc.git#86d7a89c85f324b5f6671315d9b71010ca995300"
 dependencies = [
  "env_logger 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
- "jsonrpc-core 5.1.0 (git+https://github.com/ethcore/jsonrpc.git)",
+ "jsonrpc-core 6.0.0 (git+https://github.com/ethcore/jsonrpc.git)",
  "lazy_static 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand 0.3.14 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1578,7 +1578,7 @@ dependencies = [
  "ethcore-signer 1.6.0",
  "ethcore-util 1.6.0",
  "futures 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
- "jsonrpc-core 5.1.0 (git+https://github.com/ethcore/jsonrpc.git)",
+ "jsonrpc-core 6.0.0 (git+https://github.com/ethcore/jsonrpc.git)",
  "log 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand 0.3.14 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 0.9.6 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -2503,11 +2503,11 @@ dependencies = [
 "checksum isatty 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "7408a548dc0e406b7912d9f84c261cc533c1866e047644a811c133c56041ac0c"
 "checksum itertools 0.5.9 (registry+https://github.com/rust-lang/crates.io-index)" = "d95557e7ba6b71377b0f2c3b3ae96c53f1b75a926a6901a500f557a370af730a"
 "checksum itoa 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)" = "91fd9dc2c587067de817fec4ad355e3818c3d893a78cab32a0a474c7a15bb8d5"
-"checksum jsonrpc-core 5.1.0 (git+https://github.com/ethcore/jsonrpc.git)" = "<none>"
-"checksum jsonrpc-http-server 7.0.0 (git+https://github.com/ethcore/jsonrpc.git)" = "<none>"
-"checksum jsonrpc-ipc-server 1.0.0 (git+https://github.com/ethcore/jsonrpc.git)" = "<none>"
-"checksum jsonrpc-macros 0.2.0 (git+https://github.com/ethcore/jsonrpc.git)" = "<none>"
-"checksum jsonrpc-tcp-server 1.0.0 (git+https://github.com/ethcore/jsonrpc.git)" = "<none>"
+"checksum jsonrpc-core 6.0.0 (git+https://github.com/ethcore/jsonrpc.git)" = "<none>"
+"checksum jsonrpc-http-server 6.0.0 (git+https://github.com/ethcore/jsonrpc.git)" = "<none>"
+"checksum jsonrpc-ipc-server 6.0.0 (git+https://github.com/ethcore/jsonrpc.git)" = "<none>"
+"checksum jsonrpc-macros 6.0.0 (git+https://github.com/ethcore/jsonrpc.git)" = "<none>"
+"checksum jsonrpc-tcp-server 6.0.0 (git+https://github.com/ethcore/jsonrpc.git)" = "<none>"
 "checksum kernel32-sys 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)" = "7507624b29483431c0ba2d82aece8ca6cdba9382bff4ddd0f7490560c056098d"
 "checksum language-tags 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)" = "a91d884b6667cd606bb5a69aa0c99ba811a115fc68915e7056ec08a46e93199a"
 "checksum lazy_static 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "49247ec2a285bb3dcb23cbd9c35193c025e7251bfce77c1d5da97e6362dffe7f"
diff --git a/rpc/src/v1/tests/mocked/eth.rs b/rpc/src/v1/tests/mocked/eth.rs
index 9e23cf474..dd5f63347 100644
--- a/rpc/src/v1/tests/mocked/eth.rs
+++ b/rpc/src/v1/tests/mocked/eth.rs
@@ -874,7 +874,7 @@ fn rpc_eth_send_transaction_with_bad_to() {
 		"id": 1
 	}"#;
 
-	let response = r#"{"jsonrpc":"2.0","error":{"code":-32602,"message":"Invalid params","data":null},"id":1}"#;
+	let response = r#"{"jsonrpc":"2.0","error":{"code":-32602,"message":"Invalid length.","data":null},"id":1}"#;
 
 	assert_eq!(tester.io.handle_request_sync(&request), Some(response.into()));
 }
diff --git a/rpc/src/v1/tests/mocked/parity_accounts.rs b/rpc/src/v1/tests/mocked/parity_accounts.rs
index 1c3cd2f8e..0f0a1836a 100644
--- a/rpc/src/v1/tests/mocked/parity_accounts.rs
+++ b/rpc/src/v1/tests/mocked/parity_accounts.rs
@@ -191,7 +191,7 @@ fn should_be_able_to_kill_account() {
 	let address = accounts[0];
 
 	let request = format!(r#"{{"jsonrpc": "2.0", "method": "parity_killAccount", "params": ["0xf00baba2f00baba2f00baba2f00baba2f00baba2"], "id": 1}}"#);
-	let response = r#"{"jsonrpc":"2.0","error":{"code":-32602,"message":"Invalid params","data":null},"id":1}"#;
+	let response = r#"{"jsonrpc":"2.0","error":{"code":-32602,"message":"invalid length 1, expected a tuple of size 2","data":null},"id":1}"#;
 	let res = tester.io.handle_request_sync(&request);
 	assert_eq!(res, Some(response.into()));