diff --git a/packages/api/src/SubmittableExtrinsic.ts b/packages/api/src/SubmittableExtrinsic.ts
index c54aa66a92..54b7bd0ed2 100644
--- a/packages/api/src/SubmittableExtrinsic.ts
+++ b/packages/api/src/SubmittableExtrinsic.ts
@@ -3,9 +3,8 @@
 // of the Apache-2.0 license. See the LICENSE file for details.
 
 import { KeyringPair } from '@polkadot/keyring/types';
-import { AccountId, Address, Extrinsic, ExtrinsicStatus, EventRecord, Hash, Index, Method, RuntimeVersion, SignedBlock, Struct, Text, Vector } from '@polkadot/types/index';
-import { SignatureOptions } from '@polkadot/types/ExtrinsicSignature';
-import { AnyNumber, AnyU8a, CodecCallback } from '@polkadot/types/types';
+import { AccountId, Address, Extrinsic, ExtrinsicStatus, EventRecord, Hash, Index, Method, SignedBlock, Struct, Text, Vector } from '@polkadot/types/index';
+import { CodecCallback, SignatureOptions } from '@polkadot/types/types';
 import { ApiInterface$Rx, ApiType, OnCallDefinition, Signer } from './types';
 
 import { Observable, of, combineLatest } from 'rxjs';
@@ -14,13 +13,6 @@ import { assert, isBn, isFunction, isNumber, isUndefined } from '@polkadot/util'
 
 import filterEvents from './util/filterEvents';
 
-type SignatureOptionsPartial = {
-  blockHash?: AnyU8a,
-  era?: Uint8Array,
-  nonce: AnyNumber,
-  version?: RuntimeVersion
-};
-
 type StatusCb = (result: SubmittableResult) => any;
 
 type SumbitableResultResult<CodecResult, SubscriptionResult> =
@@ -132,12 +124,12 @@ export default class SubmittableExtrinsic<CodecResult, SubscriptionResult> exten
       );
   }
 
-  private expandOptions (options: SignatureOptionsPartial): SignatureOptions {
+  private expandOptions (options: Partial<SignatureOptions>): SignatureOptions {
     return {
       blockHash: this._api.genesisHash,
       version: this._api.runtimeVersion,
       ...options
-    };
+    } as SignatureOptions;
   }
 
   send (): SumbitableResultResult<CodecResult, SubscriptionResult>;
@@ -158,10 +150,10 @@ export default class SubmittableExtrinsic<CodecResult, SubscriptionResult> exten
   // NOTE with the nonce hack, we don't add a signature overload for 2 reasons -
   //   - it makes it incompatible with the base Extrinsic
   //   - for those using TS, we would like to move them towards the new version
-  sign (account: KeyringPair, _options: SignatureOptionsPartial): SubmittableExtrinsic<CodecResult, SubscriptionResult> {
+  sign (account: KeyringPair, _options: Partial<SignatureOptions>): SubmittableExtrinsic<CodecResult, SubscriptionResult> {
     // HACK here we actually override nonce if it was specified (backwards compat for
     // the previous signature - don't let userspace break, but allow then time to upgrade)
-    const options: SignatureOptionsPartial = isBn(_options) || isNumber(_options)
+    const options: Partial<SignatureOptions> = isBn(_options) || isNumber(_options)
       ? { nonce: _options as any as number }
       : _options;
 
@@ -170,10 +162,10 @@ export default class SubmittableExtrinsic<CodecResult, SubscriptionResult> exten
     return this;
   }
 
-  signAndSend (account: KeyringPair | string | AccountId | Address, options?: Partial<SignatureOptionsPartial>): SumbitableResultResult<CodecResult, SubscriptionResult>;
+  signAndSend (account: KeyringPair | string | AccountId | Address, options?: Partial<Partial<SignatureOptions>>): SumbitableResultResult<CodecResult, SubscriptionResult>;
   signAndSend (account: KeyringPair | string | AccountId | Address, statusCb: StatusCb): SumbitableResultSubscription<CodecResult, SubscriptionResult>;
-  signAndSend (account: KeyringPair | string | AccountId | Address, _options?: Partial<SignatureOptionsPartial> | StatusCb, statusCb?: StatusCb): SumbitableResultResult<CodecResult, SubscriptionResult> | SumbitableResultSubscription<CodecResult, SubscriptionResult> {
-    let options: Partial<SignatureOptionsPartial> = {};
+  signAndSend (account: KeyringPair | string | AccountId | Address, _options?: Partial<Partial<SignatureOptions>> | StatusCb, statusCb?: StatusCb): SumbitableResultResult<CodecResult, SubscriptionResult> | SumbitableResultSubscription<CodecResult, SubscriptionResult> {
+    let options: Partial<Partial<SignatureOptions>> = {};
 
     if (isFunction(_options)) {
       statusCb = _options;
diff --git a/packages/api/src/types.ts b/packages/api/src/types.ts
index 31ca24483b..1a75105c5a 100644
--- a/packages/api/src/types.ts
+++ b/packages/api/src/types.ts
@@ -6,8 +6,7 @@ import { Observable } from 'rxjs';
 import { ProviderInterface } from '@polkadot/rpc-provider/types';
 import { RpcRxInterface$Events } from '@polkadot/rpc-rx/types';
 import { Extrinsic, Hash, Metadata, RuntimeVersion, u64 as U64 } from '@polkadot/types/index';
-import { SignatureOptions } from '@polkadot/types/ExtrinsicSignature';
-import { CodecArg, CodecCallback, RegistryTypes } from '@polkadot/types/types';
+import { CodecArg, CodecCallback, RegistryTypes, SignatureOptions } from '@polkadot/types/types';
 import { MethodFunction } from '@polkadot/types/Method';
 import { StorageFunction } from '@polkadot/types/StorageKey';
 
diff --git a/packages/api/test/util/SingleAccountSigner.ts b/packages/api/test/util/SingleAccountSigner.ts
index 379eb39ceb..b2d79c16b6 100644
--- a/packages/api/test/util/SingleAccountSigner.ts
+++ b/packages/api/test/util/SingleAccountSigner.ts
@@ -3,7 +3,8 @@
 // of the Apache-2.0 license. See the LICENSE file for details.
 
 import { KeyringPair } from '@polkadot/keyring/types';
-import { SignatureOptions } from '@polkadot/types/ExtrinsicSignature';
+import { SignatureOptions } from '@polkadot/types/types';
+
 import { Extrinsic } from '@polkadot/types/index';
 
 let id = 0;
diff --git a/packages/types/src/Extrinsic.ts b/packages/types/src/Extrinsic.ts
index a5e310b3d4..d340c6b10b 100644
--- a/packages/types/src/Extrinsic.ts
+++ b/packages/types/src/Extrinsic.ts
@@ -3,7 +3,7 @@
 // of the Apache-2.0 license. See the LICENSE file for details.
 
 import { KeyringPair } from '@polkadot/keyring/types';
-import { AnyNumber, AnyU8a, Codec } from './types';
+import { AnyNumber, AnyU8a, Codec, SignatureOptions } from './types';
 
 import { isHex, isU8a, u8aToHex, u8aToU8a } from '@polkadot/util';
 import { blake2AsU8a } from '@polkadot/util-crypto';
@@ -11,7 +11,7 @@ import { blake2AsU8a } from '@polkadot/util-crypto';
 import Compact from './codec/Compact';
 import Struct from './codec/Struct';
 import Address from './Address';
-import ExtrinsicSignature, { SignatureOptions } from './ExtrinsicSignature';
+import ExtrinsicSignature from './ExtrinsicSignature';
 import Hash from './Hash';
 import { FunctionMetadata } from './Metadata/v0/Modules';
 import Method from './Method';
diff --git a/packages/types/src/ExtrinsicSignature.ts b/packages/types/src/ExtrinsicSignature.ts
index 3d7bbfde5b..deab5bfa7b 100644
--- a/packages/types/src/ExtrinsicSignature.ts
+++ b/packages/types/src/ExtrinsicSignature.ts
@@ -3,7 +3,7 @@
 // of the Apache-2.0 license. See the LICENSE file for details.
 
 import { KeyringPair } from '@polkadot/keyring/types';
-import { AnyNumber, AnyU8a } from './types';
+import { AnyNumber, SignatureOptions } from './types';
 
 import Struct from './codec/Struct';
 import Address from './Address';
@@ -15,13 +15,6 @@ import Signature from './Signature';
 import SignaturePayload from './SignaturePayload';
 import U8 from './U8';
 
-export type SignatureOptions = {
-  blockHash: AnyU8a,
-  era?: Uint8Array,
-  nonce: AnyNumber,
-  version?: RuntimeVersion
-};
-
 export const IMMORTAL_ERA = new Uint8Array([0]);
 
 const BIT_SIGNED = 0b10000000;
@@ -155,7 +148,7 @@ export default class ExtrinsicSignature extends Struct {
       era: era || IMMORTAL_ERA,
       blockHash
     });
-    const signature = new Signature(signingPayload.sign(account, version));
+    const signature = new Signature(signingPayload.sign(account, version as RuntimeVersion));
 
     return this.injectSignature(signature, signer, signingPayload.nonce, signingPayload.era);
   }
diff --git a/packages/types/src/Header.ts b/packages/types/src/Header.ts
index 311908514d..096782ecd4 100644
--- a/packages/types/src/Header.ts
+++ b/packages/types/src/Header.ts
@@ -28,14 +28,14 @@ export type HeaderValue = {
  * A [[Block]] header
  */
 export default class Header extends Struct {
-  constructor (value?: HeaderValue | Uint8Array) {
+  constructor (value?: HeaderValue | Uint8Array | null) {
     super({
       parentHash: Hash,
       number: Compact.with(BlockNumber),
       stateRoot: Hash,
       extrinsicsRoot: Hash,
       digest: Digest
-    }, value);
+    }, value || {});
   }
 
   /**
@@ -91,11 +91,10 @@ export default class Header extends Struct {
 export class HeaderExtended extends Header {
   private _author?: AccountId;
 
-  constructor (header: Header, sessionValidators: Array<AccountId> = []) {
+  constructor (header: Header | null = null, sessionValidators: Array<AccountId> = []) {
     super(header);
 
-    const { digest: { logs } } = header;
-    const digestItem = logs.find(({ type }) => type === 'Seal');
+    const digestItem = header && header.digest && header.digest.logs.find(({ type }) => type === 'Seal');
 
     this._author = digestItem && sessionValidators.length
       ? sessionValidators[digestItem.asSeal.slot.toNumber() % sessionValidators.length]
diff --git a/packages/types/src/RuntimeVersion.ts b/packages/types/src/RuntimeVersion.ts
index 599626a196..169b4ee0d9 100644
--- a/packages/types/src/RuntimeVersion.ts
+++ b/packages/types/src/RuntimeVersion.ts
@@ -2,7 +2,7 @@
 // This software may be modified and distributed under the terms
 // of the Apache-2.0 license. See the LICENSE file for details.
 
-import { AnyNumber, AnyU8a } from './types';
+import { AnyNumber, AnyU8a, RuntimeVersionInterface } from './types';
 
 import Struct from './codec/Struct';
 import Tuple from './codec/Tuple';
@@ -69,7 +69,7 @@ type RuntimeVersionValue = {
  * @description
  * A defintion of the runtime and the associated versions thereof
  */
-export default class RuntimeVersion extends Struct {
+export default class RuntimeVersion extends Struct implements RuntimeVersionInterface {
   constructor (value?: RuntimeVersionValue | Uint8Array) {
     super({
       specName: Text,
diff --git a/packages/types/src/index.classes.ts b/packages/types/src/index.classes.ts
index 70e55d2ddc..1cc105731d 100644
--- a/packages/types/src/index.classes.ts
+++ b/packages/types/src/index.classes.ts
@@ -24,7 +24,7 @@ export { default as Bytes } from './Bytes';
 export { default as ChainProperties } from './ChainProperties';
 export { default as CodeHash } from './CodeHash';
 export { default as Data } from './Data';
-export { default as Digest } from './Digest';
+export { default as Digest, DigestItem } from './Digest';
 export { default as Event } from './Event';
 export { default as EventRecord } from './EventRecord';
 export { default as Extrinsic } from './Extrinsic';
@@ -37,7 +37,7 @@ export { default as Gas } from './Gas';
 export { default as H256 } from './H256';
 export { default as H512 } from './H512';
 export { default as Hash } from './Hash';
-export { default as Header } from './Header';
+export { default as Header, HeaderExtended } from './Header';
 export { default as Health } from './Health';
 export { default as i8 } from './I8';
 export { default as i16 } from './I16';
diff --git a/packages/types/src/types.ts b/packages/types/src/types.ts
index c3fc8bfa96..a3d8156945 100644
--- a/packages/types/src/types.ts
+++ b/packages/types/src/types.ts
@@ -71,3 +71,19 @@ export type TypeDef = { [index: string]: Codec };
 export type RegistryTypes = {
   [name: string]: Constructor | string | { [name: string]: string }
 };
+
+export interface RuntimeVersionInterface {
+  readonly apis: Array<any>;
+  readonly authoringVersion: BN;
+  readonly implName: String;
+  readonly implVersion: BN;
+  readonly specName: String;
+  readonly specVersion: BN;
+}
+
+export type SignatureOptions = {
+  blockHash: AnyU8a,
+  era?: Uint8Array,
+  nonce: AnyNumber,
+  version?: RuntimeVersionInterface
+};