diff --git a/packages/api/src/promise/types.d.ts b/packages/api/src/promise/types.d.ts
index cda7a6730a..2a91e43944 100644
--- a/packages/api/src/promise/types.d.ts
+++ b/packages/api/src/promise/types.d.ts
@@ -7,7 +7,7 @@ import { ApiBaseInterface } from '../types';
 import { Observable } from 'rxjs';
 import { ExtrinsicFunction } from '@polkadot/extrinsics/types';
 import Rpc from '@polkadot/rpc-core/index';
-import { Base } from '@polkadot/types/codec';
+import { Codec } from '@polkadot/types/types';
 import { Hash, RuntimeVersion } from '@polkadot/types/index';
 import RuntimeMetadata, { FunctionMetadata } from '@polkadot/types/Metadata';
 import { StorageFunction } from '@polkadot/types/StorageKey';
@@ -15,7 +15,7 @@ import { StorageFunction } from '@polkadot/types/StorageKey';
 import SubmittableExtrinsic from './SubmittableExtrinsic';
 
 export interface QueryableStorageFunction extends StorageFunction {
-  (arg?: any): Promise<Base | null | undefined>;
+  (arg?: any): Promise<Codec | null | undefined>;
 }
 
 export interface QueryableModuleStorage {
@@ -38,6 +38,6 @@ export interface SubmittableExtrinsics {
   [index: string]: SubmittableModuleExtrinsics;
 }
 
-export interface ApiPromiseInterface extends ApiBaseInterface<Rpc, QueryableStorage, SubmittableExtrinsics>  {
+export interface ApiPromiseInterface extends ApiBaseInterface<Rpc, QueryableStorage, SubmittableExtrinsics> {
   readonly isReady: Promise<ApiPromiseInterface>;
 }
diff --git a/packages/api/src/rx/types.d.ts b/packages/api/src/rx/types.d.ts
index e20048f1e1..cb013e00c1 100644
--- a/packages/api/src/rx/types.d.ts
+++ b/packages/api/src/rx/types.d.ts
@@ -7,7 +7,7 @@ import { ApiBaseInterface } from '../types';
 import { Observable } from 'rxjs';
 import { ExtrinsicFunction } from '@polkadot/extrinsics/types';
 import RpcRx from '@polkadot/rpc-rx/index';
-import { Base } from '@polkadot/types/codec';
+import { Codec } from '@polkadot/types/types';
 import { Hash, RuntimeVersion } from '@polkadot/types/index';
 import RuntimeMetadata, { FunctionMetadata } from '@polkadot/types/Metadata';
 import { StorageFunction } from '@polkadot/types/StorageKey';
@@ -15,7 +15,7 @@ import { StorageFunction } from '@polkadot/types/StorageKey';
 import SubmittableExtrinsic from './SubmittableExtrinsic';
 
 export interface QueryableStorageFunction extends StorageFunction {
-  (arg?: any): Observable<Base | null | undefined>;
+  (arg?: any): Observable<Codec | null | undefined>;
 }
 
 export interface QueryableModuleStorage {
@@ -38,7 +38,7 @@ export interface SubmittableExtrinsics {
   [index: string]: SubmittableModuleExtrinsics;
 }
 
-export interface ApiRxInterface extends ApiBaseInterface<RpcRx, QueryableStorage, SubmittableExtrinsics>  {
+export interface ApiRxInterface extends ApiBaseInterface<RpcRx, QueryableStorage, SubmittableExtrinsics> {
   readonly isConnected: Observable<boolean>;
   readonly isReady: Observable<ApiRxInterface>;
 }
diff --git a/packages/api/src/types.d.ts b/packages/api/src/types.d.ts
index 8c1f383305..acc4e22bdb 100644
--- a/packages/api/src/types.d.ts
+++ b/packages/api/src/types.d.ts
@@ -4,7 +4,6 @@
 
 import RpcRx from '@polkadot/rpc-rx/index';
 import { RpcRxInterface$Events } from '@polkadot/rpc-rx/types';
-import { Base } from '@polkadot/types/codec';
 import { Hash, RuntimeVersion } from '@polkadot/types/index';
 import RuntimeMetadata, { FunctionMetadata } from '@polkadot/types/Metadata';
 import { ExtrinsicFunction } from '@polkadot/extrinsics/types';
@@ -12,7 +11,7 @@ import { StorageFunction } from '@polkadot/types/StorageKey';
 
 export type ApiInterface$Events = RpcRxInterface$Events | 'ready';
 
-export interface ApiBaseInterface <R, S, E> {
+export interface ApiBaseInterface<R, S, E> {
   readonly genesisHash: Hash;
   readonly runtimeMetadata: RuntimeMetadata;
   readonly runtimeVersion: RuntimeVersion;
diff --git a/packages/rpc-rx/src/types.d.ts b/packages/rpc-rx/src/types.d.ts
index 3bf8c5d76c..7e99d9f679 100644
--- a/packages/rpc-rx/src/types.d.ts
+++ b/packages/rpc-rx/src/types.d.ts
@@ -3,7 +3,6 @@
 // of the ISC license. See the LICENSE file for details.
 
 import { ReplaySubject, Observable } from 'rxjs';
-import interfaces from '@polkadot/jsonrpc/types';
 
 export type RpcRxInterface$Method = (...params: Array<any>) => Observable<any> | ReplaySubject<any>;
 
diff --git a/packages/types/src/types.d.ts b/packages/types/src/types.d.ts
index 4ed1c49098..c6f93d35d3 100644
--- a/packages/types/src/types.d.ts
+++ b/packages/types/src/types.d.ts
@@ -29,4 +29,4 @@ export type Constructor<T = Codec> = { new(value?: any): T };
 
 export type ConstructorDef<T = Codec> = { [index: string]: Constructor<T> };
 
-export type TypeDef<T = Codec> = { [index: string]: Codec<T> };
+export type TypeDef = { [index: string]: Codec };