diff --git a/packages/app-accounts/src/Account.tsx b/packages/app-accounts/src/Account.tsx
index ff5d55ba67..feeded057f 100644
--- a/packages/app-accounts/src/Account.tsx
+++ b/packages/app-accounts/src/Account.tsx
@@ -127,35 +127,27 @@ class Account extends React.PureComponent<Props> {
   }
 
   private toggleBackup = (): void => {
-    const { isBackupOpen } = this.state;
-
-    this.setState({
+    this.setState(({ isBackupOpen }: State): Pick<State, never> => ({
       isBackupOpen: !isBackupOpen
-    });
+    }));
   }
 
   private toggleForget = (): void => {
-    const { isForgetOpen } = this.state;
-
-    this.setState({
+    this.setState(({ isForgetOpen }: State): Pick<State, never> => ({
       isForgetOpen: !isForgetOpen
-    });
+    }));
   }
 
   private togglePass = (): void => {
-    const { isPasswordOpen } = this.state;
-
-    this.setState({
+    this.setState(({ isPasswordOpen }: State): Pick<State, never> => ({
       isPasswordOpen: !isPasswordOpen
-    });
+    }));
   }
 
   private toggleTransfer = (): void => {
-    const { isTransferOpen } = this.state;
-
-    this.setState({
+    this.setState(({ isTransferOpen }: State): Pick<State, never> => ({
       isTransferOpen: !isTransferOpen
-    });
+    }));
   }
 
   private onForget = (): void => {
diff --git a/packages/app-accounts/src/Overview.tsx b/packages/app-accounts/src/Overview.tsx
index eaca80e037..44a5f8d80a 100644
--- a/packages/app-accounts/src/Overview.tsx
+++ b/packages/app-accounts/src/Overview.tsx
@@ -107,15 +107,15 @@ class Overview extends React.PureComponent<Props, State> {
   }
 
   private toggleCreate = (): void => {
-    this.setState(({ isCreateOpen }): State => ({
+    this.setState(({ isCreateOpen }): Pick<State, never> => ({
       isCreateOpen: !isCreateOpen
-    }) as unknown as State);
+    }));
   }
 
   private toggleImport = (): void => {
-    this.setState(({ isImportOpen }): State => ({
+    this.setState(({ isImportOpen }): Pick<State, never> => ({
       isImportOpen: !isImportOpen
-    }) as unknown as State);
+    }));
   }
 }
 
diff --git a/packages/app-address-book/src/Address.tsx b/packages/app-address-book/src/Address.tsx
index 537c838821..365e71e7b6 100644
--- a/packages/app-address-book/src/Address.tsx
+++ b/packages/app-address-book/src/Address.tsx
@@ -101,15 +101,15 @@ class Address extends React.PureComponent<Props, State> {
   }
 
   private toggleForget = (): void => {
-    this.setState(({ isForgetOpen }): State => ({
+    this.setState(({ isForgetOpen }): Pick<State, never> => ({
       isForgetOpen: !isForgetOpen
-    }) as unknown as State);
+    }));
   }
 
   private toggleTransfer = (): void => {
-    this.setState(({ isTransferOpen }): State => ({
+    this.setState(({ isTransferOpen }): Pick<State, never> => ({
       isTransferOpen: !isTransferOpen
-    }) as unknown as State);
+    }));
   }
 
   private onForget = (): void => {
diff --git a/packages/app-contracts/src/Codes/Upload.tsx b/packages/app-contracts/src/Codes/Upload.tsx
index 89650eb0bc..1d2457077d 100644
--- a/packages/app-contracts/src/Codes/Upload.tsx
+++ b/packages/app-contracts/src/Codes/Upload.tsx
@@ -97,7 +97,7 @@ class Upload extends ContractModal<Props, State> {
   private onSuccess = (result: SubmittableResult): void => {
     const { api } = this.props;
 
-    this.setState(({ abi, name, tags }): State | null => {
+    this.setState(({ abi, name, tags }): Pick<State, never> | null => {
       const section = api.tx.contracts ? 'contracts' : 'contract';
       const record = result.findRecord(section, 'CodeStored');
 
@@ -115,7 +115,7 @@ class Upload extends ContractModal<Props, State> {
           });
       }
 
-      return { isBusy: false } as unknown as State;
+      return { isBusy: false };
     });
   }
 }
diff --git a/packages/app-contracts/src/Contracts/Call.tsx b/packages/app-contracts/src/Contracts/Call.tsx
index 61125c43f5..ff0f7fe21c 100644
--- a/packages/app-contracts/src/Contracts/Call.tsx
+++ b/packages/app-contracts/src/Contracts/Call.tsx
@@ -49,14 +49,14 @@ class Call extends TxComponent<Props, State> {
 
   public state: State = this.defaultState;
 
-  public static getDerivedStateFromProps ({ address: propsAddress, method: propsMethod, isOpen }: Props, { address, method }: State): State | null {
+  public static getDerivedStateFromProps ({ address: propsAddress, method: propsMethod, isOpen }: Props, { address, method }: State): Pick<State, never> | null {
     if (!isOpen) {
       return {
         address: null,
         method: null,
         contractAbi: null,
         isAddressValid: false
-      } as unknown as State;
+      };
     }
 
     return {
@@ -74,7 +74,7 @@ class Call extends TxComponent<Props, State> {
           ? { method: propsMethod }
           : {}
       )
-    } as unknown as State;
+    };
   }
 
   public render (): React.ReactNode {
@@ -113,10 +113,10 @@ class Call extends TxComponent<Props, State> {
     }
 
     const methodOptions = contractAbi
-      ? Object.keys(contractAbi.messages).map((key) => {
+      ? Object.keys(contractAbi.messages).map((key): { key: string; text: string; value: string } => {
         const fn = contractAbi.messages[key];
         const type = fn.type ? `: ${fn.type}` : '';
-        const args = fn.args.map(({ name, type }) => `${name}: ${type}`);
+        const args = fn.args.map(({ name, type }): string => `${name}: ${type}`);
         const text = `${key}(${args.join(', ')})${type}`;
 
         return {
@@ -276,13 +276,13 @@ class Call extends TxComponent<Props, State> {
   }
 
   private toggleBusy = (): void => {
-    this.setState(({ isBusy }): State => ({
+    this.setState(({ isBusy }): Pick<State, never> => ({
       isBusy: !isBusy
-    }) as unknown as State);
+    }));
   }
 
   private reset = (): void => {
-    this.setState((state: State): State => {
+    this.setState((state: State): Pick<State, never> => {
       if (!state.isBusy) {
         return {
           ...state,
@@ -290,7 +290,7 @@ class Call extends TxComponent<Props, State> {
         };
       }
 
-      return {} as unknown as State;
+      return {};
     });
   }
 
diff --git a/packages/app-contracts/src/Deploy.tsx b/packages/app-contracts/src/Deploy.tsx
index bb9afea0cb..403653c925 100644
--- a/packages/app-contracts/src/Deploy.tsx
+++ b/packages/app-contracts/src/Deploy.tsx
@@ -14,7 +14,7 @@ import { Abi } from '@polkadot/api-contract';
 import { withApi, withMulti } from '@polkadot/ui-api';
 import keyring from '@polkadot/ui-keyring';
 import { Button, Dropdown, InputBalance, TxButton } from '@polkadot/ui-app';
-import { AccountId, getTypeDef } from '@polkadot/types';
+import { AccountId, TypeDef, getTypeDef } from '@polkadot/types';
 import createValues from '@polkadot/ui-params/values';
 
 import ContractModal, { ContractModalProps, ContractModalState } from './Modal';
@@ -70,7 +70,7 @@ class Deploy extends ContractModal<Props, State> {
     const { codeHash, constructOptions, contractAbi, endowment, isAbiSupplied, isBusy, isHashValid } = this.state;
 
     const isEndowValid = !endowment.isZero();
-    const codeOptions = store.getAllCode().map(({ json: { codeHash, name } }) => ({
+    const codeOptions = store.getAllCode().map(({ json: { codeHash, name } }): { text: string; value: string } => ({
       text: `${name} (${codeHash})`,
       value: codeHash
     }));
@@ -179,7 +179,7 @@ class Deploy extends ContractModal<Props, State> {
         contractAbi,
         isAbiValid: !!contractAbi,
         params: createValues(
-          contractAbi.deploy.args.map(({ name, type }) => ({
+          contractAbi.deploy.args.map(({ name, type }): { type: TypeDef } => ({
             type: getTypeDef(type, name)
           }))
         )
@@ -196,7 +196,7 @@ class Deploy extends ContractModal<Props, State> {
     }
   }
 
-  private getCodeState = (codeHash: string | null = null): State => {
+  private getCodeState = (codeHash: string | null = null): Pick<State, never> => {
     if (codeHash) {
       const code = store.getCode(codeHash);
 
@@ -210,11 +210,11 @@ class Deploy extends ContractModal<Props, State> {
           isHashValid: true,
           isNameValid: true,
           ...this.getContractAbiState(json.abi, contractAbi)
-        } as unknown as State;
+        };
       }
     }
 
-    return {} as unknown as State;
+    return {};
   }
 
   private constructCall = (): any[] => {
@@ -256,7 +256,7 @@ class Deploy extends ContractModal<Props, State> {
     if (record) {
       const address = record.event.data[1] as unknown as AccountId;
 
-      this.setState(({ abi, name, tags }): State | unknown => {
+      this.setState(({ abi, name, tags }): Pick<State, never> | unknown => {
         if (!abi || !name) {
           return;
         }
@@ -274,7 +274,7 @@ class Deploy extends ContractModal<Props, State> {
 
         this.onClose();
 
-        return { isBusy: false } as unknown as State;
+        return { isBusy: false };
       });
     }
   }
diff --git a/packages/app-contracts/src/Params.tsx b/packages/app-contracts/src/Params.tsx
index 230691b58c..0885cc72a6 100644
--- a/packages/app-contracts/src/Params.tsx
+++ b/packages/app-contracts/src/Params.tsx
@@ -38,7 +38,7 @@ export default class Params extends React.PureComponent<Props, State> {
         name,
         type: getTypeDef(type, name)
       }))
-    } as unknown as State;
+    };
   }
 
   public render (): React.ReactNode {
diff --git a/packages/app-contracts/src/index.tsx b/packages/app-contracts/src/index.tsx
index f2fc0a1d5a..19e75a7a4a 100644
--- a/packages/app-contracts/src/index.tsx
+++ b/packages/app-contracts/src/index.tsx
@@ -51,12 +51,12 @@ class App extends React.PureComponent<Props, State> {
     });
   }
 
-  public static getDerivedStateFromProps ({ contracts }: Props): State {
+  public static getDerivedStateFromProps ({ contracts }: Props): Pick<State, never> {
     const hasContracts = !!contracts && Object.keys(contracts).length >= 1;
 
     return {
       hasContracts
-    } as unknown as State;
+    };
   }
 
   public render (): React.ReactNode {
diff --git a/packages/app-democracy/src/Overview/Voting.tsx b/packages/app-democracy/src/Overview/Voting.tsx
index 77877593a1..07a1c80b65 100644
--- a/packages/app-democracy/src/Overview/Voting.tsx
+++ b/packages/app-democracy/src/Overview/Voting.tsx
@@ -21,7 +21,7 @@ interface Props extends I18nProps {
 interface State {
   accountId?: string;
   isVotingOpen: boolean;
-  voteOptions: { text: React.ReactNode, value: boolean }[];
+  voteOptions: { text: React.ReactNode; value: boolean }[];
   voteValue: boolean;
 }
 
@@ -65,7 +65,7 @@ class Voting extends React.PureComponent<Props, State> {
     );
   }
 
-  private renderModal () {
+  private renderModal (): React.ReactNode {
     const { referendumId, t } = this.props;
     const { accountId, isVotingOpen, voteOptions, voteValue } = this.state;
 
@@ -128,9 +128,9 @@ class Voting extends React.PureComponent<Props, State> {
   }
 
   private toggleVoting = (): void => {
-    this.setState(({ isVotingOpen }): State => ({
+    this.setState(({ isVotingOpen }): Pick<State, never> => ({
       isVotingOpen: !isVotingOpen
-    }) as unknown as State);
+    }));
   }
 }
 
diff --git a/packages/app-staking/src/Actions/Account/index.tsx b/packages/app-staking/src/Actions/Account/index.tsx
index 25b6a0cc6c..3ea7eeec81 100644
--- a/packages/app-staking/src/Actions/Account/index.tsx
+++ b/packages/app-staking/src/Actions/Account/index.tsx
@@ -81,7 +81,7 @@ class Account extends React.PureComponent<Props, State> {
     stashId: null
   };
 
-  public static getDerivedStateFromProps ({ accountId, staking_info }: Props): State | null {
+  public static getDerivedStateFromProps ({ accountId, staking_info }: Props): Pick<State, never> | null {
     if (!staking_info) {
       return null;
     }
@@ -102,7 +102,7 @@ class Account extends React.PureComponent<Props, State> {
       stakingLedger,
       stashId: toIdString(stashId),
       validatorPrefs
-    } as unknown as State;
+    };
   }
 
   public render (): React.ReactNode {
@@ -526,51 +526,51 @@ class Account extends React.PureComponent<Props, State> {
   }
 
   private toggleBondExtra = (): void => {
-    this.setState(({ isBondExtraOpen }): State => ({
+    this.setState(({ isBondExtraOpen }): Pick<State, never> => ({
       isBondExtraOpen: !isBondExtraOpen
-    }) as unknown as State);
+    }));
   }
 
   private toggleNominate = (): void => {
-    this.setState(({ isNominateOpen }): State => ({
+    this.setState(({ isNominateOpen }): Pick<State, never> => ({
       isNominateOpen: !isNominateOpen
-    }) as unknown as State);
+    }));
   }
 
   private toggleSetControllerAccount = (): void => {
-    this.setState(({ isSetControllerAccountOpen }): State => ({
+    this.setState(({ isSetControllerAccountOpen }): Pick<State, never> => ({
       isSetControllerAccountOpen: !isSetControllerAccountOpen
-    }) as unknown as State);
+    }));
   }
 
   private toggleSetRewardDestination = (): void => {
-    this.setState(({ isSetRewardDestinationOpen }): State => ({
+    this.setState(({ isSetRewardDestinationOpen }): Pick<State, never> => ({
       isSetRewardDestinationOpen: !isSetRewardDestinationOpen
-    }) as unknown as State);
+    }));
   }
 
   private toggleSetSessionAccount = (): void => {
-    this.setState(({ isSetSessionAccountOpen }): State => ({
+    this.setState(({ isSetSessionAccountOpen }): Pick<State, never> => ({
       isSetSessionAccountOpen: !isSetSessionAccountOpen
-    }) as unknown as State);
+    }));
   }
 
   private toggleSettingPopup = (): void => {
-    this.setState(({ isSettingPopupOpen }): State => ({
+    this.setState(({ isSettingPopupOpen }): Pick<State, never> => ({
       isSettingPopupOpen: !isSettingPopupOpen
-    }) as unknown as State);
+    }));
   }
 
   private toggleUnbond = (): void => {
-    this.setState(({ isUnbondOpen }): State => ({
+    this.setState(({ isUnbondOpen }): Pick<State, never> => ({
       isUnbondOpen: !isUnbondOpen
-    }) as unknown as State);
+    }));
   }
 
   private toggleValidate = (): void => {
-    this.setState(({ isValidateOpen }): State => ({
+    this.setState(({ isValidateOpen }): Pick<State, never> => ({
       isValidateOpen: !isValidateOpen
-    }) as unknown as State);
+    }));
   }
 }
 
diff --git a/packages/app-staking/src/Overview/Address.tsx b/packages/app-staking/src/Overview/Address.tsx
index 3df5811db6..524b29a460 100644
--- a/packages/app-staking/src/Overview/Address.tsx
+++ b/packages/app-staking/src/Overview/Address.tsx
@@ -55,7 +55,7 @@ class Address extends React.PureComponent<Props, State> {
     };
   }
 
-  public static getDerivedStateFromProps ({ staking_info }: Props, prevState: State): State | null {
+  public static getDerivedStateFromProps ({ staking_info }: Props, prevState: State): Pick<State, never> | null {
     if (!staking_info) {
       return null;
     }
@@ -73,7 +73,7 @@ class Address extends React.PureComponent<Props, State> {
       stashTotal: stakingLedger
         ? formatBalance(stakingLedger.total)
         : prevState.stashTotal
-    } as unknown as State;
+    };
   }
 
   public render (): React.ReactNode {
diff --git a/packages/app-staking/src/index.tsx b/packages/app-staking/src/index.tsx
index 3c0335fefc..1ad91d5bc6 100644
--- a/packages/app-staking/src/index.tsx
+++ b/packages/app-staking/src/index.tsx
@@ -65,7 +65,7 @@ class App extends React.PureComponent<Props, State> {
     };
   }
 
-  public static getDerivedStateFromProps ({ allStashesAndControllers = [[], []], currentValidatorsControllersV1OrStashesV2 = [], staking_recentlyOffline = [] }: Props): State {
+  public static getDerivedStateFromProps ({ allStashesAndControllers = [[], []], currentValidatorsControllersV1OrStashesV2 = [], staking_recentlyOffline = [] }: Props): Pick<State, never> {
     return {
       allControllers: allStashesAndControllers[1].filter((optId): boolean => optId.isSome).map((accountId): string =>
         accountId.unwrap().toString()
@@ -89,7 +89,7 @@ class App extends React.PureComponent<Props, State> {
 
           return result;
         }, {} as unknown as RecentlyOfflineMap)
-    } as unknown as State;
+    };
   }
 
   public render (): React.ReactNode {
diff --git a/packages/ui-app/src/LabelHelp.tsx b/packages/ui-app/src/LabelHelp.tsx
index 6bcefb87f3..fae359d0db 100644
--- a/packages/ui-app/src/LabelHelp.tsx
+++ b/packages/ui-app/src/LabelHelp.tsx
@@ -58,8 +58,8 @@ export default class LabelHelp extends React.PureComponent<Props, State> {
   }
 
   private toggleTooltip = (): void => {
-    this.setState(({ tooltipOpen }): State => ({
+    this.setState(({ tooltipOpen }): Pick<State, never> => ({
       tooltipOpen: !tooltipOpen
-    }) as unknown as State);
+    }));
   }
 }
diff --git a/packages/ui-params/src/Param/Enum.tsx b/packages/ui-params/src/Param/Enum.tsx
index d0f7a8e1b5..f37a552f84 100644
--- a/packages/ui-params/src/Param/Enum.tsx
+++ b/packages/ui-params/src/Param/Enum.tsx
@@ -95,9 +95,9 @@ export default class EnumParam extends React.PureComponent<Props, State> {
   }
 
   private onChange = (value: string): void => {
-    this.setState(({ sub }): State => ({
+    this.setState(({ sub }): Pick<State, never> => ({
       def: sub.find(({ name }): boolean => name === value) || null
-    }) as unknown as State);
+    }));
   }
 
   private onChangeParam = ([{ isValid, value }]: RawParam[]): void => {
diff --git a/packages/ui-params/src/Param/Vector.tsx b/packages/ui-params/src/Param/Vector.tsx
index cce7340654..d47203617e 100644
--- a/packages/ui-params/src/Param/Vector.tsx
+++ b/packages/ui-params/src/Param/Vector.tsx
@@ -111,13 +111,13 @@ class Vector extends React.PureComponent<Props, State> {
   private onChange = (index: number): (value: RawParam) => void => {
     return (value: RawParam): void => {
       this.setState(
-        ({ values }: State): State => ({
+        ({ values }: State): Pick<State, never> => ({
           values: values.map((svalue, sindex): RawParam =>
             (sindex === index)
               ? value
               : svalue
           )
-        } as unknown as State),
+        }),
         (): void => {
           const { values } = this.state;
           const { onChange } = this.props;
@@ -132,7 +132,7 @@ class Vector extends React.PureComponent<Props, State> {
   }
 
   private rowAdd = (): void => {
-    this.setState(({ values }: State, { type: { sub } }: Props): State => {
+    this.setState(({ values }: State, { type: { sub } }: Props): Pick<State, never> => {
       const value = getInitValue(sub as TypeDef);
 
       return {
@@ -140,14 +140,14 @@ class Vector extends React.PureComponent<Props, State> {
           isValid: !isUndefined(value),
           value
         })
-      } as unknown as State;
+      };
     });
   }
 
   private rowRemove = (): void => {
-    this.setState(({ values }: State): State => ({
+    this.setState(({ values }: State): Pick<State, never> => ({
       values: values.slice(0, values.length - 1)
-    } as unknown as State));
+    }));
   }
 }
 
diff --git a/packages/ui-params/src/index.tsx b/packages/ui-params/src/index.tsx
index f6956a05c1..b7a62db30e 100644
--- a/packages/ui-params/src/index.tsx
+++ b/packages/ui-params/src/index.tsx
@@ -126,7 +126,7 @@ class Params extends React.PureComponent<Props, State> {
     const { isValid = false, value } = newValue;
 
     this.setState(
-      (prevState: State): State => ({
+      (prevState: State): Pick<State, never> => ({
         values: (prevState.values || []).map((prev, index): RawParam =>
           index !== at
             ? prev
@@ -135,7 +135,7 @@ class Params extends React.PureComponent<Props, State> {
               value
             }
         )
-      } as unknown as State),
+      }),
       this.triggerUpdate
     );
   }