diff --git a/packages/api-derive/src/bundle.ts b/packages/api-derive/src/bundle.ts
index 9975e90960..84fed9de9e 100644
--- a/packages/api-derive/src/bundle.ts
+++ b/packages/api-derive/src/bundle.ts
@@ -39,12 +39,12 @@ export { lazyDeriveSection };
 export const derive = { accounts, balances, bounties, chain, contracts, council, crowdloan, democracy, elections, imOnline, membership, parachains, session, society, staking, technicalCommittee, treasury, tx };
 
 type DeriveSection<Section> = {
-  [Method in keyof Section]: Section[Method] extends AnyFunction
-    ? ReturnType<Section[Method]> // ReturnType<Section[Method]> will be the inner function, i.e. without (api) argument
+  [M in keyof Section]: Section[M] extends AnyFunction
+    ? ReturnType<Section[M]> // ReturnType<Section[Method]> will be the inner function, i.e. without (api) argument
     : never;
 };
 type DeriveAllSections<AllSections> = {
-  [Section in keyof AllSections]: DeriveSection<AllSections[Section]>
+  [S in keyof AllSections]: DeriveSection<AllSections[S]>
 };
 
 type DeriveCreator = (instanceId: string, api: ApiInterfaceRx) => (...args: unknown[]) => Observable<any>;
diff --git a/packages/api-derive/src/staking/cache.ts b/packages/api-derive/src/staking/cache.ts
new file mode 100644
index 0000000000..fb3afc2045
--- /dev/null
+++ b/packages/api-derive/src/staking/cache.ts
@@ -0,0 +1,27 @@
+// Copyright 2017-2021 @polkadot/api-derive authors & contributors
+// SPDX-License-Identifier: Apache-2.0
+
+import type { EraIndex } from '@polkadot/types/interfaces';
+
+import { deriveCache } from '../util';
+
+export function getEraCache <T> (CACHE_KEY: string, era: EraIndex, withActive?: boolean): [string, T | undefined] {
+  const cacheKey = `${CACHE_KEY}-${era.toString()}`;
+
+  return [
+    cacheKey,
+    withActive
+      ? undefined
+      : deriveCache.get<T>(cacheKey)
+  ];
+}
+
+export function getEraMultiCache <T> (CACHE_KEY: string, eras: EraIndex[], withActive?: boolean): T[] {
+  const cached: T[] = withActive
+    ? []
+    : eras
+      .map((e) => deriveCache.get<T>(`${CACHE_KEY}-${e.toString()}`))
+      .filter((v): v is T => !!v);
+
+  return cached;
+}
diff --git a/packages/api-derive/src/staking/erasExposure.ts b/packages/api-derive/src/staking/erasExposure.ts
index 21638ce218..fcd71d2705 100644
--- a/packages/api-derive/src/staking/erasExposure.ts
+++ b/packages/api-derive/src/staking/erasExposure.ts
@@ -8,9 +8,11 @@ import type { AccountId, EraIndex } from '@polkadot/types/interfaces';
 import type { PalletStakingExposure } from '@polkadot/types/lookup';
 import type { DeriveEraExposure, DeriveEraNominatorExposure, DeriveEraValidatorExposure } from '../types';
 
-import { combineLatest, map, of, switchMap } from 'rxjs';
+import { combineLatest, map, of } from 'rxjs';
 
 import { deriveCache, memo } from '../util';
+import { getEraCache } from './cache';
+import { erasHistoricApply } from './util';
 
 type KeysAndExposures = [StorageKey<[EraIndex, AccountId]>, PalletStakingExposure][];
 
@@ -38,10 +40,7 @@ function mapStakers (era: EraIndex, stakers: KeysAndExposures): DeriveEraExposur
 
 export function _eraExposure (instanceId: string, api: ApiInterfaceRx): (era: EraIndex, withActive: boolean) => Observable<DeriveEraExposure> {
   return memo(instanceId, (era: EraIndex, withActive: boolean): Observable<DeriveEraExposure> => {
-    const cacheKey = `${CACHE_KEY}-${era.toString()}`;
-    const cached = withActive
-      ? undefined
-      : deriveCache.get<DeriveEraExposure>(cacheKey);
+    const [cacheKey, cached] = getEraCache<DeriveEraExposure>(CACHE_KEY, era, withActive);
 
     return cached
       ? of(cached)
@@ -71,10 +70,4 @@ export function _erasExposure (instanceId: string, api: ApiInterfaceRx): (eras:
   );
 }
 
-export function erasExposure (instanceId: string, api: ApiInterfaceRx): (withActive?: boolean) => Observable<DeriveEraExposure[]> {
-  return memo(instanceId, (withActive = false): Observable<DeriveEraExposure[]> =>
-    api.derive.staking.erasHistoric(withActive).pipe(
-      switchMap((eras) => api.derive.staking._erasExposure(eras, withActive))
-    )
-  );
-}
+export const erasExposure = erasHistoricApply('_erasExposure');
diff --git a/packages/api-derive/src/staking/erasPoints.ts b/packages/api-derive/src/staking/erasPoints.ts
index c2949937eb..5d09c457e3 100644
--- a/packages/api-derive/src/staking/erasPoints.ts
+++ b/packages/api-derive/src/staking/erasPoints.ts
@@ -7,12 +7,13 @@ import type { EraIndex } from '@polkadot/types/interfaces';
 import type { PalletStakingEraRewardPoints } from '@polkadot/types/lookup';
 import type { DeriveEraPoints, DeriveEraValPoints } from '../types';
 
-import { map, of, switchMap } from 'rxjs';
+import { map, of } from 'rxjs';
 
 import { BN_ZERO } from '@polkadot/util';
 
 import { deriveCache, memo } from '../util';
-import { filterEras } from './util';
+import { getEraMultiCache } from './cache';
+import { erasHistoricApply, filterEras } from './util';
 
 const CACHE_KEY = 'eraPoints';
 
@@ -40,11 +41,7 @@ export function _erasPoints (instanceId: string, api: ApiInterfaceRx): (eras: Er
       return of([]);
     }
 
-    const cached: DeriveEraPoints[] = withActive
-      ? []
-      : eras
-        .map((era) => deriveCache.get<DeriveEraPoints>(`${CACHE_KEY}-${era.toString()}`))
-        .filter((value): value is DeriveEraPoints => !!value);
+    const cached = getEraMultiCache<DeriveEraPoints>(CACHE_KEY, eras, withActive);
     const remaining = filterEras(eras, cached);
 
     return !remaining.length
@@ -64,10 +61,4 @@ export function _erasPoints (instanceId: string, api: ApiInterfaceRx): (eras: Er
   });
 }
 
-export function erasPoints (instanceId: string, api: ApiInterfaceRx): (withActive?: boolean) => Observable<DeriveEraPoints[]> {
-  return memo(instanceId, (withActive = false): Observable<DeriveEraPoints[]> =>
-    api.derive.staking.erasHistoric(withActive).pipe(
-      switchMap((eras) => api.derive.staking._erasPoints(eras, withActive))
-    )
-  );
-}
+export const erasPoints = erasHistoricApply('_erasPoints');
diff --git a/packages/api-derive/src/staking/erasPrefs.ts b/packages/api-derive/src/staking/erasPrefs.ts
index 6ebcfc129a..a329de47b7 100644
--- a/packages/api-derive/src/staking/erasPrefs.ts
+++ b/packages/api-derive/src/staking/erasPrefs.ts
@@ -8,9 +8,11 @@ import type { EraIndex } from '@polkadot/types/interfaces';
 import type { PalletStakingValidatorPrefs } from '@polkadot/types/lookup';
 import type { DeriveEraPrefs, DeriveEraValPrefs } from '../types';
 
-import { combineLatest, map, of, switchMap } from 'rxjs';
+import { combineLatest, map, of } from 'rxjs';
 
 import { deriveCache, memo } from '../util';
+import { getEraCache } from './cache';
+import { erasHistoricApply } from './util';
 
 const CACHE_KEY = 'eraPrefs';
 
@@ -26,10 +28,7 @@ function mapPrefs (era: EraIndex, all: [StorageKey, PalletStakingValidatorPrefs]
 
 export function _eraPrefs (instanceId: string, api: ApiInterfaceRx): (era: EraIndex, withActive: boolean) => Observable<DeriveEraPrefs> {
   return memo(instanceId, (era: EraIndex, withActive: boolean): Observable<DeriveEraPrefs> => {
-    const cacheKey = `${CACHE_KEY}-${era.toString()}`;
-    const cached = withActive
-      ? undefined
-      : deriveCache.get<DeriveEraPrefs>(cacheKey);
+    const [cacheKey, cached] = getEraCache<DeriveEraPrefs>(CACHE_KEY, era, withActive);
 
     return cached
       ? of(cached)
@@ -59,10 +58,4 @@ export function _erasPrefs (instanceId: string, api: ApiInterfaceRx): (eras: Era
   );
 }
 
-export function erasPrefs (instanceId: string, api: ApiInterfaceRx): (withActive?: boolean) => Observable<DeriveEraPrefs[]> {
-  return memo(instanceId, (withActive = false): Observable<DeriveEraPrefs[]> =>
-    api.derive.staking.erasHistoric(withActive).pipe(
-      switchMap((eras) => api.derive.staking._erasPrefs(eras, withActive))
-    )
-  );
-}
+export const erasPrefs = erasHistoricApply('_erasPrefs');
diff --git a/packages/api-derive/src/staking/erasRewards.ts b/packages/api-derive/src/staking/erasRewards.ts
index 22572fe471..7eaabf35b1 100644
--- a/packages/api-derive/src/staking/erasRewards.ts
+++ b/packages/api-derive/src/staking/erasRewards.ts
@@ -7,10 +7,11 @@ import type { Option } from '@polkadot/types';
 import type { Balance, EraIndex } from '@polkadot/types/interfaces';
 import type { DeriveEraRewards } from '../types';
 
-import { map, of, switchMap } from 'rxjs';
+import { map, of } from 'rxjs';
 
 import { deriveCache, memo } from '../util';
-import { filterEras } from './util';
+import { getEraMultiCache } from './cache';
+import { erasHistoricApply, filterEras } from './util';
 
 const CACHE_KEY = 'eraRewards';
 
@@ -27,11 +28,7 @@ export function _erasRewards (instanceId: string, api: ApiInterfaceRx): (eras: E
       return of([]);
     }
 
-    const cached: DeriveEraRewards[] = withActive
-      ? []
-      : eras
-        .map((era) => deriveCache.get<DeriveEraRewards>(`${CACHE_KEY}-${era.toString()}`))
-        .filter((value): value is DeriveEraRewards => !!value);
+    const cached = getEraMultiCache<DeriveEraRewards>(CACHE_KEY, eras, withActive);
     const remaining = filterEras(eras, cached);
 
     if (!remaining.length) {
@@ -53,10 +50,4 @@ export function _erasRewards (instanceId: string, api: ApiInterfaceRx): (eras: E
   });
 }
 
-export function erasRewards (instanceId: string, api: ApiInterfaceRx): (withActive?: boolean) => Observable<DeriveEraRewards[]> {
-  return memo(instanceId, (withActive = false): Observable<DeriveEraRewards[]> =>
-    api.derive.staking.erasHistoric(withActive).pipe(
-      switchMap((eras) => api.derive.staking._erasRewards(eras, withActive))
-    )
-  );
-}
+export const erasRewards = erasHistoricApply('_erasRewards');
diff --git a/packages/api-derive/src/staking/erasSlashes.ts b/packages/api-derive/src/staking/erasSlashes.ts
index a74e4b0822..2de58f9ece 100644
--- a/packages/api-derive/src/staking/erasSlashes.ts
+++ b/packages/api-derive/src/staking/erasSlashes.ts
@@ -8,9 +8,11 @@ import type { BalanceOf, EraIndex, Perbill } from '@polkadot/types/interfaces';
 import type { ITuple } from '@polkadot/types/types';
 import type { DeriveEraSlashes, DeriveEraValSlash } from '../types';
 
-import { combineLatest, map, of, switchMap } from 'rxjs';
+import { combineLatest, map, of } from 'rxjs';
 
 import { deriveCache, memo } from '../util';
+import { getEraCache } from './cache';
+import { erasHistoricApply } from './util';
 
 const CACHE_KEY = 'eraSlashes';
 
@@ -31,10 +33,7 @@ function mapSlashes (era: EraIndex, noms: [StorageKey, Option<BalanceOf>][], val
 
 export function _eraSlashes (instanceId: string, api: ApiInterfaceRx): (era: EraIndex, withActive: boolean) => Observable<DeriveEraSlashes> {
   return memo(instanceId, (era: EraIndex, withActive: boolean): Observable<DeriveEraSlashes> => {
-    const cacheKey = `${CACHE_KEY}-${era.toString()}`;
-    const cached = withActive
-      ? undefined
-      : deriveCache.get<DeriveEraSlashes>(cacheKey);
+    const [cacheKey, cached] = getEraCache<DeriveEraSlashes>(CACHE_KEY, era, withActive);
 
     return cached
       ? of(cached)
@@ -69,10 +68,4 @@ export function _erasSlashes (instanceId: string, api: ApiInterfaceRx): (eras: E
   );
 }
 
-export function erasSlashes (instanceId: string, api: ApiInterfaceRx): (withActive?: boolean) => Observable<DeriveEraSlashes[]> {
-  return memo(instanceId, (withActive = false): Observable<DeriveEraSlashes[]> =>
-    api.derive.staking.erasHistoric(withActive).pipe(
-      switchMap((eras) => api.derive.staking._erasSlashes(eras, withActive))
-    )
-  );
-}
+export const erasSlashes = erasHistoricApply('_erasSlashes');
diff --git a/packages/api-derive/src/staking/ownExposure.ts b/packages/api-derive/src/staking/ownExposure.ts
index 70261342e4..6c54fbd63f 100644
--- a/packages/api-derive/src/staking/ownExposure.ts
+++ b/packages/api-derive/src/staking/ownExposure.ts
@@ -7,9 +7,10 @@ import type { EraIndex } from '@polkadot/types/interfaces';
 import type { PalletStakingExposure } from '@polkadot/types/lookup';
 import type { DeriveOwnExposure } from '../types';
 
-import { map, of, switchMap } from 'rxjs';
+import { map, of } from 'rxjs';
 
 import { memo } from '../util';
+import { erasHistoricApplyAccount } from './util';
 
 export function _ownExposures (instanceId: string, api: ApiInterfaceRx): (accountId: Uint8Array | string, eras: EraIndex[], withActive: boolean) => Observable<DeriveOwnExposure[]> {
   // eslint-disable-next-line @typescript-eslint/no-unused-vars
@@ -35,12 +36,4 @@ export function ownExposure (instanceId: string, api: ApiInterfaceRx): (accountI
   );
 }
 
-export function ownExposures (instanceId: string, api: ApiInterfaceRx): (accountId: Uint8Array | string, withActive?: boolean) => Observable<DeriveOwnExposure[]> {
-  return memo(instanceId, (accountId: Uint8Array | string, withActive = false): Observable<DeriveOwnExposure[]> => {
-    return api.derive.staking.erasHistoric(withActive).pipe(
-      switchMap((eras) =>
-        api.derive.staking._ownExposures(accountId, eras, withActive)
-      )
-    );
-  });
-}
+export const ownExposures = erasHistoricApplyAccount('_ownExposures');
diff --git a/packages/api-derive/src/staking/ownSlashes.ts b/packages/api-derive/src/staking/ownSlashes.ts
index 9812151c86..c2b894ae5b 100644
--- a/packages/api-derive/src/staking/ownSlashes.ts
+++ b/packages/api-derive/src/staking/ownSlashes.ts
@@ -8,9 +8,10 @@ import type { BalanceOf, EraIndex, Perbill } from '@polkadot/types/interfaces';
 import type { ITuple } from '@polkadot/types/types';
 import type { DeriveStakerSlashes } from '../types';
 
-import { map, of, switchMap } from 'rxjs';
+import { map, of } from 'rxjs';
 
 import { memo } from '../util';
+import { erasHistoricApplyAccount } from './util';
 
 export function _ownSlashes (instanceId: string, api: ApiInterfaceRx): (accountId: Uint8Array | string, eras: EraIndex[], withActive: boolean) => Observable<DeriveStakerSlashes[]> {
   // eslint-disable-next-line @typescript-eslint/no-unused-vars
@@ -41,12 +42,4 @@ export function ownSlash (instanceId: string, api: ApiInterfaceRx): (accountId:
   );
 }
 
-export function ownSlashes (instanceId: string, api: ApiInterfaceRx): (accountId: Uint8Array | string, withActive?: boolean) => Observable<DeriveStakerSlashes[]> {
-  return memo(instanceId, (accountId: Uint8Array | string, withActive = false): Observable<DeriveStakerSlashes[]> => {
-    return api.derive.staking.erasHistoric(withActive).pipe(
-      switchMap((eras) =>
-        api.derive.staking._ownSlashes(accountId, eras, withActive)
-      )
-    );
-  });
-}
+export const ownSlashes = erasHistoricApplyAccount('_ownSlashes');
diff --git a/packages/api-derive/src/staking/stakerPoints.ts b/packages/api-derive/src/staking/stakerPoints.ts
index b559407aa0..24444cfc0c 100644
--- a/packages/api-derive/src/staking/stakerPoints.ts
+++ b/packages/api-derive/src/staking/stakerPoints.ts
@@ -6,9 +6,10 @@ import type { ApiInterfaceRx } from '@polkadot/api/types';
 import type { EraIndex } from '@polkadot/types/interfaces';
 import type { DeriveStakerPoints } from '../types';
 
-import { map, switchMap } from 'rxjs';
+import { map } from 'rxjs';
 
 import { memo } from '../util';
+import { erasHistoricApplyAccount } from './util';
 
 export function _stakerPoints (instanceId: string, api: ApiInterfaceRx): (accountId: Uint8Array | string, eras: EraIndex[], withActive: boolean) => Observable<DeriveStakerPoints[]> {
   return memo(instanceId, (accountId: Uint8Array | string, eras: EraIndex[], withActive: boolean): Observable<DeriveStakerPoints[]> => {
@@ -26,10 +27,4 @@ export function _stakerPoints (instanceId: string, api: ApiInterfaceRx): (accoun
   });
 }
 
-export function stakerPoints (instanceId: string, api: ApiInterfaceRx): (accountId: Uint8Array | string, withActive?: boolean) => Observable<DeriveStakerPoints[]> {
-  return memo(instanceId, (accountId: Uint8Array | string, withActive = false): Observable<DeriveStakerPoints[]> =>
-    api.derive.staking.erasHistoric(withActive).pipe(
-      switchMap((eras) => api.derive.staking._stakerPoints(accountId, eras, withActive))
-    )
-  );
-}
+export const stakerPoints = erasHistoricApplyAccount('_stakerPoints');
diff --git a/packages/api-derive/src/staking/stakerPrefs.ts b/packages/api-derive/src/staking/stakerPrefs.ts
index 842172db28..19e94a7022 100644
--- a/packages/api-derive/src/staking/stakerPrefs.ts
+++ b/packages/api-derive/src/staking/stakerPrefs.ts
@@ -6,9 +6,10 @@ import type { ApiInterfaceRx } from '@polkadot/api/types';
 import type { EraIndex } from '@polkadot/types/interfaces';
 import type { DeriveStakerPrefs } from '../types';
 
-import { map, switchMap } from 'rxjs';
+import { map } from 'rxjs';
 
 import { memo } from '../util';
+import { erasHistoricApplyAccount } from './util';
 
 export function _stakerPrefs (instanceId: string, api: ApiInterfaceRx): (accountId: Uint8Array | string, eras: EraIndex[], withActive: boolean) => Observable<DeriveStakerPrefs[]> {
   // eslint-disable-next-line @typescript-eslint/no-unused-vars
@@ -24,10 +25,4 @@ export function _stakerPrefs (instanceId: string, api: ApiInterfaceRx): (account
   );
 }
 
-export function stakerPrefs (instanceId: string, api: ApiInterfaceRx): (accountId: Uint8Array | string, withActive?: boolean) => Observable<DeriveStakerPrefs[]> {
-  return memo(instanceId, (accountId: Uint8Array | string, withActive = false): Observable<DeriveStakerPrefs[]> =>
-    api.derive.staking.erasHistoric(withActive).pipe(
-      switchMap((eras) => api.derive.staking._stakerPrefs(accountId, eras, withActive))
-    )
-  );
-}
+export const stakerPrefs = erasHistoricApplyAccount('_stakerPrefs');
diff --git a/packages/api-derive/src/staking/stakerSlashes.ts b/packages/api-derive/src/staking/stakerSlashes.ts
index 0a7fd2ca8e..4731a5a918 100644
--- a/packages/api-derive/src/staking/stakerSlashes.ts
+++ b/packages/api-derive/src/staking/stakerSlashes.ts
@@ -6,9 +6,10 @@ import type { ApiInterfaceRx } from '@polkadot/api/types';
 import type { EraIndex } from '@polkadot/types/interfaces';
 import type { DeriveStakerSlashes } from '../types';
 
-import { map, switchMap } from 'rxjs';
+import { map } from 'rxjs';
 
 import { memo } from '../util';
+import { erasHistoricApplyAccount } from './util';
 
 export function _stakerSlashes (instanceId: string, api: ApiInterfaceRx): (accountId: Uint8Array | string, eras: EraIndex[], withActive: boolean) => Observable<DeriveStakerSlashes[]> {
   return memo(instanceId, (accountId: Uint8Array | string, eras: EraIndex[], withActive: boolean): Observable<DeriveStakerSlashes[]> => {
@@ -25,10 +26,4 @@ export function _stakerSlashes (instanceId: string, api: ApiInterfaceRx): (accou
   });
 }
 
-export function stakerSlashes (instanceId: string, api: ApiInterfaceRx): (accountId: Uint8Array | string, withActive?: boolean) => Observable<DeriveStakerSlashes[]> {
-  return memo(instanceId, (accountId: Uint8Array | string, withActive = false): Observable<DeriveStakerSlashes[]> =>
-    api.derive.staking.erasHistoric(withActive).pipe(
-      switchMap((eras) => api.derive.staking._stakerSlashes(accountId, eras, withActive))
-    )
-  );
-}
+export const stakerSlashes = erasHistoricApplyAccount('_stakerSlashes');
diff --git a/packages/api-derive/src/staking/util.ts b/packages/api-derive/src/staking/util.ts
index cc344b682c..9dcd69fccd 100644
--- a/packages/api-derive/src/staking/util.ts
+++ b/packages/api-derive/src/staking/util.ts
@@ -1,8 +1,38 @@
 // Copyright 2017-2021 @polkadot/api-derive authors & contributors
 // SPDX-License-Identifier: Apache-2.0
 
+import type { ApiInterfaceRx } from '@polkadot/api/types';
 import type { EraIndex } from '@polkadot/types/interfaces';
+import type { ExactDerive } from '../bundle';
+
+import { switchMap } from 'rxjs';
+
+import { memo } from '../util';
+
+type ApplyReturn<T extends keyof ExactDerive['staking']> = ReturnType<ExactDerive['staking'][T]>;
 
 export function filterEras <T extends { era: EraIndex }> (eras: EraIndex[], list: T[]): EraIndex[] {
   return eras.filter((era) => !list.some((entry) => era.eq(entry.era)));
 }
+
+export function erasHistoricApply <F extends '_erasExposure' | '_erasPoints' | '_erasPrefs' | '_erasRewards' | '_erasSlashes'> (fn: F): (instanceId: string, api: ApiInterfaceRx) => (withActive?: boolean) => ApplyReturn<F> {
+  return (instanceId: string, api: ApiInterfaceRx) =>
+    // Cannot quite get the typing right, but it is right in the code
+    // eslint-disable-next-line @typescript-eslint/no-unsafe-return
+    memo(instanceId, (withActive = false) =>
+      api.derive.staking.erasHistoric(withActive).pipe(
+        switchMap((e) => api.derive.staking[fn](e, withActive))
+      )
+    ) as any;
+}
+
+export function erasHistoricApplyAccount <F extends '_ownExposures' | '_ownSlashes' | '_stakerPoints' | '_stakerPrefs' | '_stakerSlashes'> (fn: F): (instanceId: string, api: ApiInterfaceRx) => (accountId: string | Uint8Array, withActive?: boolean) => ApplyReturn<F> {
+  return (instanceId: string, api: ApiInterfaceRx) =>
+    // Cannot quite get the typing right, but it is right in the code
+    // eslint-disable-next-line @typescript-eslint/no-unsafe-return
+    memo(instanceId, (accountId: string | Uint8Array, withActive = false) =>
+      api.derive.staking.erasHistoric(withActive).pipe(
+        switchMap((e) => api.derive.staking[fn](accountId, e, withActive))
+      )
+    ) as any;
+}