diff --git a/modules/signals/spec/deep-signal.spec.ts b/modules/signals/spec/deep-signal.spec.ts
new file mode 100644
index 0000000000..0fdd89795e
--- /dev/null
+++ b/modules/signals/spec/deep-signal.spec.ts
@@ -0,0 +1,161 @@
+import { isSignal, signal } from '@angular/core';
+import { toDeepSignal } from '../src/deep-signal';
+
+describe('toDeepSignal', () => {
+  it('creates deep signals for plain objects', () => {
+    const sig = signal({ m: { s: 't' } });
+    const deepSig = toDeepSignal(sig);
+
+    expect(sig).not.toBe(deepSig);
+
+    expect(isSignal(deepSig)).toBe(true);
+    expect(deepSig()).toEqual({ m: { s: 't' } });
+
+    expect(isSignal(deepSig.m)).toBe(true);
+    expect(deepSig.m()).toEqual({ s: 't' });
+
+    expect(isSignal(deepSig.m.s)).toBe(true);
+    expect(deepSig.m.s()).toBe('t');
+  });
+
+  it('creates deep signals for custom class instances', () => {
+    class User {
+      constructor(readonly firstName: string) {}
+    }
+
+    class UserState {
+      constructor(readonly user: User) {}
+    }
+
+    const sig = signal(new UserState(new User('John')));
+    const deepSig = toDeepSignal(sig);
+
+    expect(sig).not.toBe(deepSig);
+
+    expect(isSignal(deepSig)).toBe(true);
+    expect(deepSig()).toEqual({ user: { firstName: 'John' } });
+
+    expect(isSignal(deepSig.user)).toBe(true);
+    expect(deepSig.user()).toEqual({ firstName: 'John' });
+
+    expect(isSignal(deepSig.user.firstName)).toBe(true);
+    expect(deepSig.user.firstName()).toBe('John');
+  });
+
+  it('does not create deep signals for primitives', () => {
+    const num = signal(0);
+    const str = signal('str');
+    const bool = signal(true);
+
+    const deepNum = toDeepSignal(num);
+    const deepStr = toDeepSignal(str);
+    const deepBool = toDeepSignal(bool);
+
+    expect(deepNum).toBe(num);
+    expect(deepStr).toBe(str);
+    expect(deepBool).toBe(bool);
+  });
+
+  it('does not create deep signals for iterables', () => {
+    const array = signal([]);
+    const set = signal(new Set());
+    const map = signal(new Map());
+    const uintArray = signal(new Uint32Array());
+    const floatArray = signal(new Float64Array());
+
+    const deepArray = toDeepSignal(array);
+    const deepSet = toDeepSignal(set);
+    const deepMap = toDeepSignal(map);
+    const deepUintArray = toDeepSignal(uintArray);
+    const deepFloatArray = toDeepSignal(floatArray);
+
+    expect(deepArray).toBe(array);
+    expect(deepSet).toBe(set);
+    expect(deepMap).toBe(map);
+    expect(deepUintArray).toBe(uintArray);
+    expect(deepFloatArray).toBe(floatArray);
+  });
+
+  it('does not create deep signals for built-in object types', () => {
+    const weakSet = signal(new WeakSet());
+    const weakMap = signal(new WeakMap());
+    const promise = signal(Promise.resolve(10));
+    const date = signal(new Date());
+    const error = signal(new Error());
+    const regExp = signal(new RegExp(''));
+    const arrayBuffer = signal(new ArrayBuffer(10));
+    const dataView = signal(new DataView(new ArrayBuffer(10)));
+
+    const deepWeakSet = toDeepSignal(weakSet);
+    const deepWeakMap = toDeepSignal(weakMap);
+    const deepPromise = toDeepSignal(promise);
+    const deepDate = toDeepSignal(date);
+    const deepError = toDeepSignal(error);
+    const deepRegExp = toDeepSignal(regExp);
+    const deepArrayBuffer = toDeepSignal(arrayBuffer);
+    const deepDataView = toDeepSignal(dataView);
+
+    expect(deepWeakSet).toBe(weakSet);
+    expect(deepWeakMap).toBe(weakMap);
+    expect(deepPromise).toBe(promise);
+    expect(deepDate).toBe(date);
+    expect(deepError).toBe(error);
+    expect(deepRegExp).toBe(regExp);
+    expect(deepArrayBuffer).toBe(arrayBuffer);
+    expect(deepDataView).toBe(dataView);
+  });
+
+  it('does not create deep signals for functions', () => {
+    const fn1 = signal(new Function());
+    const fn2 = signal(function () {});
+    const fn3 = signal(() => {});
+
+    const deepFn1 = toDeepSignal(fn1);
+    const deepFn2 = toDeepSignal(fn2);
+    const deepFn3 = toDeepSignal(fn3);
+
+    expect(deepFn1).toBe(fn1);
+    expect(deepFn2).toBe(fn2);
+    expect(deepFn3).toBe(fn3);
+  });
+
+  it('does not create deep signals for custom class instances that are iterables', () => {
+    class CustomArray extends Array {}
+
+    class CustomSet extends Set {}
+
+    class CustomFloatArray extends Float32Array {}
+
+    const array = signal(new CustomArray());
+    const floatArray = signal(new CustomFloatArray());
+    const set = signal(new CustomSet());
+
+    const deepArray = toDeepSignal(array);
+    const deepFloatArray = toDeepSignal(floatArray);
+    const deepSet = toDeepSignal(set);
+
+    expect(deepArray).toBe(array);
+    expect(deepFloatArray).toBe(floatArray);
+    expect(deepSet).toBe(set);
+  });
+
+  it('does not create deep signals for custom class instances that extend built-in object types', () => {
+    class CustomWeakMap extends WeakMap {}
+
+    class CustomError extends Error {}
+
+    class CustomArrayBuffer extends ArrayBuffer {}
+
+    const weakMap = signal(new CustomWeakMap());
+    const error = signal(new CustomError());
+    const arrayBuffer = signal(new CustomArrayBuffer(10));
+
+    const deepWeakMap = toDeepSignal(weakMap);
+    const deepError = toDeepSignal(error);
+    const deepArrayBuffer = toDeepSignal(arrayBuffer);
+
+    expect(deepWeakMap).toBe(weakMap);
+    expect(deepError).toBe(error);
+    expect(deepArrayBuffer).toBe(arrayBuffer);
+  });
+});
diff --git a/modules/signals/spec/types/signal-state.types.spec.ts b/modules/signals/spec/types/signal-state.types.spec.ts
index c9edeab141..e4bf63b2ad 100644
--- a/modules/signals/spec/types/signal-state.types.spec.ts
+++ b/modules/signals/spec/types/signal-state.types.spec.ts
@@ -118,37 +118,85 @@ describe('signalState', () => {
     expectSnippet(snippet).toInfer('set', 'Signal<Set<{ foo: number; }>>');
   });
 
-  it('does not create deep signals for an array', () => {
+  it('does not create deep signals for iterables', () => {
     const snippet = `
-      const state = signalState<string[]>([]);
-      declare const stateKeys: keyof typeof state;
+      const arrayState = signalState<string[]>([]);
+      declare const arrayStateKeys: keyof typeof arrayState;
+
+      const setState = signalState(new Set<number>());
+      declare const setStateKeys: keyof typeof setState;
+
+      const mapState = signalState(new Map<number, { bar: boolean }>());
+      declare const mapStateKeys: keyof typeof mapState;
+
+      const uintArrayState = signalState(new Uint8ClampedArray());
+      declare const uintArrayStateKeys: keyof typeof uintArrayState;
     `;
 
     expectSnippet(snippet).toSucceed();
 
     expectSnippet(snippet).toInfer(
-      'stateKeys',
+      'arrayStateKeys',
       'unique symbol | keyof Signal<string[]>'
     );
+
+    expectSnippet(snippet).toInfer(
+      'setStateKeys',
+      'unique symbol | keyof Signal<Set<number>>'
+    );
+
+    expectSnippet(snippet).toInfer(
+      'mapStateKeys',
+      'unique symbol | keyof Signal<Map<number, { bar: boolean; }>>'
+    );
+
+    expectSnippet(snippet).toInfer(
+      'uintArrayStateKeys',
+      'unique symbol | keyof Signal<Uint8ClampedArray>'
+    );
   });
 
-  it('does not create deep signals for Map', () => {
+  it('does not create deep signals for built-in object types', () => {
     const snippet = `
-      const state = signalState(new Map<number, { bar: boolean }>());
-      declare const stateKeys: keyof typeof state;
+      const weakSetState = signalState(new WeakSet<{ foo: string }>());
+      declare const weakSetStateKeys: keyof typeof weakSetState;
+
+      const dateState = signalState(new Date());
+      declare const dateStateKeys: keyof typeof dateState;
+
+      const errorState = signalState(new Error());
+      declare const errorStateKeys: keyof typeof errorState;
+
+      const regExpState = signalState(new RegExp(''));
+      declare const regExpStateKeys: keyof typeof regExpState;
     `;
 
     expectSnippet(snippet).toSucceed();
 
     expectSnippet(snippet).toInfer(
-      'stateKeys',
-      'unique symbol | keyof Signal<Map<number, { bar: boolean; }>>'
+      'weakSetStateKeys',
+      'unique symbol | keyof Signal<WeakSet<{ foo: string; }>>'
+    );
+
+    expectSnippet(snippet).toInfer(
+      'dateStateKeys',
+      'unique symbol | keyof Signal<Date>'
+    );
+
+    expectSnippet(snippet).toInfer(
+      'errorStateKeys',
+      'unique symbol | keyof Signal<Error>'
+    );
+
+    expectSnippet(snippet).toInfer(
+      'regExpStateKeys',
+      'unique symbol | keyof Signal<RegExp>'
     );
   });
 
-  it('does not create deep signals for Set', () => {
+  it('does not create deep signals for functions', () => {
     const snippet = `
-      const state = signalState(new Set<number>());
+      const state = signalState(() => {});
       declare const stateKeys: keyof typeof state;
     `;
 
@@ -156,7 +204,7 @@ describe('signalState', () => {
 
     expectSnippet(snippet).toInfer(
       'stateKeys',
-      'unique symbol | keyof Signal<Set<number>>'
+      'unique symbol | keyof Signal<() => void>'
     );
   });
 
diff --git a/modules/signals/spec/types/signal-store.types.spec.ts b/modules/signals/spec/types/signal-store.types.spec.ts
index aeb0ab73f4..6854f27064 100644
--- a/modules/signals/spec/types/signal-store.types.spec.ts
+++ b/modules/signals/spec/types/signal-store.types.spec.ts
@@ -163,33 +163,63 @@ describe('signalStore', () => {
     expectSnippet(snippet).toInfer('set', 'Signal<Set<number>>');
   });
 
-  it('does not create deep signals when state type is an array', () => {
+  it('does not create deep signals when state type is an iterable', () => {
     const snippet = `
-      const Store = signalStore(withState<number[]>([]));
-      const store = new Store();
-      declare const storeKeys: keyof typeof store;
+      const ArrayStore = signalStore(withState<number[]>([]));
+      const arrayStore = new ArrayStore();
+      declare const arrayStoreKeys: keyof typeof arrayStore;
+
+      const SetStore = signalStore(withState(new Set<{ foo: string }>()));
+      const setStore = new SetStore();
+      declare const setStoreKeys: keyof typeof setStore;
+
+      const MapStore = signalStore(withState(new Map<string, { foo: number }>()));
+      const mapStore = new MapStore();
+      declare const mapStoreKeys: keyof typeof mapStore;
+
+      const FloatArrayStore = signalStore(withState(new Float32Array()));
+      const floatArrayStore = new FloatArrayStore();
+      declare const floatArrayStoreKeys: keyof typeof floatArrayStore;
     `;
 
     expectSnippet(snippet).toSucceed();
 
-    expectSnippet(snippet).toInfer('storeKeys', 'unique symbol');
+    expectSnippet(snippet).toInfer('arrayStoreKeys', 'unique symbol');
+    expectSnippet(snippet).toInfer('setStoreKeys', 'unique symbol');
+    expectSnippet(snippet).toInfer('mapStoreKeys', 'unique symbol');
+    expectSnippet(snippet).toInfer('floatArrayStoreKeys', 'unique symbol');
   });
 
-  it('does not create deep signals when state type is Map', () => {
+  it('does not create deep signals when state type is a built-in object type', () => {
     const snippet = `
-      const Store = signalStore(withState(new Map<string, { foo: number }>()));
-      const store = new Store();
-      declare const storeKeys: keyof typeof store;
+      const WeakMapStore = signalStore(withState(new WeakMap<{ foo: string }, { bar: number }>()));
+      const weakMapStore = new WeakMapStore();
+      declare const weakMapStoreKeys: keyof typeof weakMapStore;
+
+      const DateStore = signalStore(withState(new Date()));
+      const dateStore = new DateStore();
+      declare const dateStoreKeys: keyof typeof dateStore;
+
+      const ErrorStore = signalStore(withState(new Error()));
+      const errorStore = new ErrorStore();
+      declare const errorStoreKeys: keyof typeof errorStore;
+
+      const RegExpStore = signalStore(withState(new RegExp('')));
+      const regExpStore = new RegExpStore();
+      declare const regExpStoreKeys: keyof typeof regExpStore;
     `;
 
     expectSnippet(snippet).toSucceed();
 
-    expectSnippet(snippet).toInfer('storeKeys', 'unique symbol');
+    expectSnippet(snippet).toInfer('weakMapStoreKeys', 'unique symbol');
+    expectSnippet(snippet).toInfer('dateStoreKeys', 'unique symbol');
+    expectSnippet(snippet).toInfer('errorStoreKeys', 'unique symbol');
+    expectSnippet(snippet).toInfer('regExpStoreKeys', 'unique symbol');
   });
 
-  it('does not create deep signals when state type is Set', () => {
+  it('does not create deep signals when state type is a function', () => {
     const snippet = `
-      const Store = signalStore(withState(new Set<{ foo: string }>()));
+      const Store = signalStore(withState(() => () => {}));
       const store = new Store();
       declare const storeKeys: keyof typeof store;
     `;
diff --git a/modules/signals/src/deep-signal.ts b/modules/signals/src/deep-signal.ts
index 733e085fc7..7610d9ad8e 100644
--- a/modules/signals/src/deep-signal.ts
+++ b/modules/signals/src/deep-signal.ts
@@ -46,6 +46,38 @@ export function toDeepSignal<T>(signal: Signal<T>): DeepSignal<T> {
   });
 }
 
+const nonRecords = [
+  WeakSet,
+  WeakMap,
+  Promise,
+  Date,
+  Error,
+  RegExp,
+  ArrayBuffer,
+  DataView,
+  Function,
+];
+
 function isRecord(value: unknown): value is Record<string, unknown> {
-  return value?.constructor === Object;
+  if (value === null || typeof value !== 'object' || isIterable(value)) {
+    return false;
+  }
+
+  let proto = Object.getPrototypeOf(value);
+  if (proto === Object.prototype) {
+    return true;
+  }
+
+  while (proto && proto !== Object.prototype) {
+    if (nonRecords.includes(proto.constructor)) {
+      return false;
+    }
+    proto = Object.getPrototypeOf(proto);
+  }
+
+  return proto === Object.prototype;
+}
+
+function isIterable(value: any): value is Iterable<any> {
+  return typeof value?.[Symbol.iterator] === 'function';
 }
diff --git a/modules/signals/src/ts-helpers.ts b/modules/signals/src/ts-helpers.ts
index f7df5cdb77..bf94d5965b 100644
--- a/modules/signals/src/ts-helpers.ts
+++ b/modules/signals/src/ts-helpers.ts
@@ -1,13 +1,19 @@
+type NonRecord =
+  | Iterable<any>
+  | WeakSet<any>
+  | WeakMap<any, any>
+  | Promise<any>
+  | Date
+  | Error
+  | RegExp
+  | ArrayBuffer
+  | DataView
+  | Function;
+
 export type Prettify<T> = { [K in keyof T]: T[K] } & {};
 
 export type IsRecord<T> = T extends object
-  ? T extends unknown[]
-    ? false
-    : T extends Set<unknown>
-    ? false
-    : T extends Map<unknown, unknown>
-    ? false
-    : T extends Function
+  ? T extends NonRecord
     ? false
     : true
   : false;