diff --git a/src/classes/version/version.ts b/src/classes/version/version.ts
index 83f425458..32383b267 100644
--- a/src/classes/version/version.ts
+++ b/src/classes/version/version.ts
@@ -6,6 +6,7 @@ import { Transaction } from '../transaction';
 import { removeTablesApi, setApiOnPlace, parseIndexSyntax } from './schema-helpers';
 import { exceptions } from '../../errors';
 import { createTableSchema } from '../../helpers/table-schema';
+import { LooseStoresSpec } from '../../public/types/strictly-typed-schema';
 import { nop, promisableChain } from '../../functions/chaining-functions';
 
 /** class Version
@@ -38,11 +39,22 @@ export class Version implements IVersion {
     });
   }
 
-  stores(stores: { [key: string]: string | null; }): IVersion {
+  stores(stores: LooseStoresSpec): IVersion {
     const db = this.db;
-    this._cfg.storesSource = this._cfg.storesSource ?
-      extend(this._cfg.storesSource, stores) :
-      stores;
+    const bwCompatStores = {} as { [key: string]: string | null };
+    for (const table of keys(stores)) {
+      const spec = stores[table];
+      if (spec === null) {
+        bwCompatStores[table] = null;
+      } else if (typeof spec === 'string') {
+        bwCompatStores[table] = spec;
+      } else if (Array.isArray(spec)) {
+        bwCompatStores[table] = spec.join(',');
+      }
+    }
+    this._cfg.storesSource = this._cfg.storesSource
+      ? extend(this._cfg.storesSource, bwCompatStores)
+      : bwCompatStores;
     const versions = db._versions;
 
     // Derive stores from earlier versions if they are not explicitely specified as null or a new syntax.
diff --git a/src/public/types/dexie.d.ts b/src/public/types/dexie.d.ts
index 67189f651..a3697949f 100644
--- a/src/public/types/dexie.d.ts
+++ b/src/public/types/dexie.d.ts
@@ -13,7 +13,7 @@ import { IndexableType } from './indexable-type';
 import { DBCore } from './dbcore';
 import { Middleware, DexieStacks } from './middleware';
 
-export type TableProp<DX extends Dexie> = {
+export type TableProp<DX> = {
   [K in keyof DX]: DX[K] extends {schema: any, get: any, put: any, add: any, where: any} ? K : never;
 }[keyof DX] & string;
 
diff --git a/src/public/types/strictly-typed-schema.d.ts b/src/public/types/strictly-typed-schema.d.ts
new file mode 100644
index 000000000..03b666e80
--- /dev/null
+++ b/src/public/types/strictly-typed-schema.d.ts
@@ -0,0 +1,148 @@
+import { Dexie, TableProp } from './dexie';
+import { IndexableType, IndexableTypeArray } from './indexable-type';
+import { Table } from './table';
+
+// Indexable arrays on root level only
+type ArrayProps<T> = {
+  [K in keyof T]: K extends string
+    ? T[K] extends IndexableTypeArray
+      ? K
+      : never
+    : never;
+}[keyof T];
+
+type NumberProps<T> = {
+  [K in keyof T]: K extends string ? (T[K] extends number ? K : never) : never;
+}[keyof T];
+
+type StringProps<T> = {
+  [K in keyof T]: K extends string ? (T[K] extends string ? K : never) : never;
+}[keyof T];
+
+type IgnoreObjects =
+  | RegExp
+  | DataView
+  | Map<any, any>
+  | Set<any>
+  | CryptoKey
+  | Promise<any>
+  | ReadableStream<any>
+  | ReadableStreamDefaultReader<any>
+  | ReadableStreamDefaultController<any>
+  | { whenLoaded: Promise<any> }; // Y.Doc
+
+// Nested indexable arrays (configurable max depth)
+type ArrayKeyPaths<
+  T,
+  MAXDEPTH = 'III',
+  CURRDEPTH extends string = ''
+> = CURRDEPTH extends MAXDEPTH
+  ? ArrayProps<T>
+  :
+      | ArrayKeyPaths<T, MAXDEPTH, `${CURRDEPTH}I`>
+      | {
+          [K in keyof T]: K extends string
+            ? T[K] extends object
+              ? `${K}.${keyof T[K] extends string
+                  ? ArrayKeyPaths<T[K], MAXDEPTH, `${CURRDEPTH}I`>
+                  : never}`
+              : never
+            : never;
+        }[keyof T];
+
+// Indexable root properties
+type IndexableProps<T> = {
+  [K in keyof T]: K extends string
+    ? T[K] extends IndexableType
+      ? K
+      : never
+    : never;
+}[keyof T];
+
+// Keypaths of indexable properties and nested properteis (configurable MAXDEPTH)
+type IndexableKeyPaths<
+  T,
+  MAXDEPTH = 'III',
+  CURRDEPTH extends string = ''
+> = CURRDEPTH extends MAXDEPTH
+  ? IndexableProps<T>
+  : {
+      [K in keyof T]: K extends string
+        ? T[K] extends IndexableType
+          ? K
+          : T[K] extends IgnoreObjects
+          ? never
+          : T[K] extends object
+          ? `${K}.${keyof T[K] extends string
+              ? IndexableKeyPaths<T[K], MAXDEPTH, `${CURRDEPTH}I`>
+              : never}`
+          : never
+        : never;
+    }[keyof T];
+
+// Compound index syntax
+type Combo<
+  T,
+  MAXDEPTH = 'III',
+  CURRDEPTH extends string = ''
+> = CURRDEPTH extends MAXDEPTH
+  ? never
+  : {
+      [P in keyof T]: P extends string
+        ? keyof Omit<T, P> extends never
+          ? P
+          : P | `${P}+${Combo<Omit<T, P>, MAXDEPTH, `${CURRDEPTH}I`>}`
+        : never;
+    }[keyof T];
+
+type IndexablePathObj<T> = {
+  [P in IndexableKeyPaths<T>]: true;
+};
+
+type SingleCombound<T> = {
+  [P in IndexableKeyPaths<T>]: `[${P}]`;
+}[IndexableKeyPaths<T>];
+
+// -------
+
+// Main generic type for Dexie index syntax
+type DexieIndexSyntax<T> =
+  | `&${IndexableKeyPaths<T>}`
+  | IndexableKeyPaths<T>
+  | `*${ArrayKeyPaths<T>}` // Wildcard for array keys
+  | Exclude<`[${Combo<IndexablePathObj<T>>}]`, SingleCombound<T>> // Combined non-array keys
+  | `&${Exclude<`[${Combo<Pick<T, IndexableProps<T>>>}]`, SingleCombound<T>>}`; // Combined non-array keys
+
+type DexiePrimaryKeySyntax<T> =
+  | ''
+  | `++${NumberProps<T>}`
+  | `@${StringProps<T>}`
+  | `&${IndexableKeyPaths<T>}`
+  | `${IndexableKeyPaths<T>}`
+  | `${IndexableKeyPaths<T>}:Y.Doc`
+  | `${Exclude<`[${Combo<IndexablePathObj<T>>}]`, SingleCombound<T>>}` // Combined non-array keys
+  | `&${Exclude<`[${Combo<IndexablePathObj<T>>}]`, SingleCombound<T>>}`;
+
+type TypedProperties<T> = {
+  [K in keyof T]: K extends string
+    ? T[K] extends { whenLoaded: Promise<any> }
+      ? `${K}:Y.Doc`
+      : never
+    : never;
+}[keyof T];
+
+type LooseStoresSpec = { [tableName: string]: string | null | string[] };
+
+type StoresSpec<DX extends Dexie> =  TableProp<Omit<DX, keyof Dexie>> extends never ? LooseStoresSpec :
+  Dexie extends DX ? LooseStoresSpec :
+    {
+      [TN in TableProp<DX>]?: DX[TN] extends Table<infer T, any, any>
+        ?
+            | string
+            | null
+            | [
+                DexiePrimaryKeySyntax<T>,
+                ...(DexieIndexSyntax<T> | TypedProperties<T>)[]
+              ]
+        : string | string[] | null;
+    };
diff --git a/src/public/types/version.d.ts b/src/public/types/version.d.ts
index 8bc06b8b0..f6f9d412c 100644
--- a/src/public/types/version.d.ts
+++ b/src/public/types/version.d.ts
@@ -1,6 +1,7 @@
 import { Transaction } from "./transaction";
+import { LooseStoresSpec, StoresSpec } from "./strictly-typed-schema";
 
 export interface Version {
-  stores(schema: { [tableName: string]: string | null }): Version;
+  stores(schema: LooseStoresSpec): Version;
   upgrade(fn: (trans: Transaction) => PromiseLike<any> | void): Version;
 }