diff --git a/package.json b/package.json
index e7a09d8..f94eb08 100644
--- a/package.json
+++ b/package.json
@@ -11,7 +11,7 @@
 		"@angular/compiler-cli": "^18.1.0",
 		"@angular/core": "^18.1.0",
 		"@ngrx/component-store": "^18.0.0",
-		"@ngrx/signals": "18.0.0-rc.2",
+		"@ngrx/signals": "^18.0.0",
 		"@ngrx/store": "^18.0.0",
 		"@types/jest": "^29.5.12",
 		"cpy-cli": "^5.0.0",
diff --git a/src/package.json b/src/package.json
index 153c477..8537cbf 100644
--- a/src/package.json
+++ b/src/package.json
@@ -28,9 +28,9 @@
 	},
 	"peerDependencies": {
 		"immer": ">= 7.0.0",
-		"@ngrx/component-store": ">= 13.0.0",
-		"@ngrx/store": ">= 13.0.0",
-		"@ngrx/signals": ">= 17.1.1 < 18.0.0"
+		"@ngrx/component-store": ">= 18.0.0",
+		"@ngrx/store": ">= 18.0.0",
+		"@ngrx/signals": ">= 18.0.0"
 	},
 	"peerDependenciesMeta": {
 		"@ngrx/component-store": {
diff --git a/src/signals/index.ts b/src/signals/index.ts
index 5a6c45f..223bdd8 100644
--- a/src/signals/index.ts
+++ b/src/signals/index.ts
@@ -1,4 +1,4 @@
-import { PartialStateUpdater, patchState, StateSignal } from '@ngrx/signals';
+import { PartialStateUpdater, patchState, WritableStateSource,  Prettify } from '@ngrx/signals';
 import { immerReducer } from 'ngrx-immer';
 
 export type ImmerStateUpdater<State extends object> = (state: State) => void;
@@ -12,9 +12,7 @@ function toFullStateUpdater<State extends object>(updater: PartialStateUpdater<S
 		return;
 	};
 }
-
-type Prettify<T> = { [K in keyof T]: T[K] } & {};
-export function immerPatchState<State extends object>(state: StateSignal<State>, ...updaters: Array<Partial<Prettify<State>> | PartialStateUpdater<Prettify<State>> | ImmerStateUpdater<Prettify<State>>>) {
+export function immerPatchState<State extends object>(state: WritableStateSource<State>, ...updaters: Array<Partial<Prettify<State>> | PartialStateUpdater<Prettify<State>> | ImmerStateUpdater<Prettify<State>>>): void {
 	const immerUpdaters = updaters.map(updater => {
 		if (typeof updater === 'function') {
 			return immerReducer(toFullStateUpdater(updater)) as unknown as PartialStateUpdater<State & {}>;
diff --git a/src/signals/tests/immer-patch-state.jest.ts b/src/signals/tests/immer-patch-state.jest.ts
index 48e9792..4fc48a2 100644
--- a/src/signals/tests/immer-patch-state.jest.ts
+++ b/src/signals/tests/immer-patch-state.jest.ts
@@ -2,26 +2,28 @@ import {
 	PartialStateUpdater,
 	signalStore,
 	withComputed,
+	withMethods,
 	withState,
 } from '@ngrx/signals';
 import { immerPatchState } from 'ngrx-immer/signals';
 import { computed, effect } from '@angular/core';
 import { TestBed } from '@angular/core/testing';
 
-const UserState = signalStore(
-	withState({
-		id: 1,
-		name: { firstname: 'Konrad', lastname: 'Schultz' },
-		address: { city: 'Vienna', zip: '1010' },
-	}),
-	withComputed(({ name }) => ({
-		prettyName: computed(() => `${name.firstname()} ${name.lastname()}`),
-	})),
-);
-
-describe('immerPatchState', () => {
+describe('immerPatchState (unprotected)', () => {
+	const UnprotectedUserState = signalStore(
+		{ protectedState: false },
+		withState({
+			id: 1,
+			name: { firstname: 'Konrad', lastname: 'Schultz' },
+			address: { city: 'Vienna', zip: '1010' },
+		}),
+		withComputed(({ name }) => ({
+			prettyName: computed(() => `${name.firstname()} ${name.lastname()}`),
+		})),
+	);
+
 	const setup = () => {
-		return new UserState();
+		return new UnprotectedUserState();
 	};
 
 	it('smoketest', () => {
@@ -192,3 +194,51 @@ describe('immerPatchState', () => {
 		});
 	});
 });
+
+describe('immerPatchState (protected)', () => {
+	const ProtectedUserState = signalStore(
+		{ protectedState: true },
+		withState({
+			id: 1,
+			name: { firstname: 'Konrad', lastname: 'Schultz' },
+			address: { city: 'Vienna', zip: '1010' },
+		}),
+		withComputed(({ name }) => ({
+			prettyName: computed(() => `${name.firstname()} ${name.lastname()}`),
+		})),
+		withMethods((store) => ({
+			setName: (name: {firstname:string, lastname:string}) => immerPatchState(store, { name }),
+			incrementId: () => immerPatchState(store, state => {
+				state.id++;
+			}),
+		}))
+	);
+
+	const setup = () => {
+		return new ProtectedUserState();
+	};
+
+	it('smoketest', () => {
+		const userState = setup();
+		expect(userState.id()).toBe(1);
+	});
+
+	it('state is protected and cannot be updated from the outside', () => {
+		const userState = setup();
+
+		expect(() => {
+			// @ts-ignore
+			immerPatchState(userState, (state) => ({ number: 1 }));
+		}).toThrow();
+	});
+
+	it('allows patching protected state using withMethods', () => {
+		const userState = setup();
+
+		userState.incrementId();
+		userState.setName({ firstname: 'Lucy', lastname: 'Sanders' });
+
+		expect(userState.prettyName()).toBe('Lucy Sanders');
+		expect(userState.id()).toBe(2);
+	});
+});