diff --git a/modules/signals/entities/src/helpers.ts b/modules/signals/entities/src/helpers.ts
index 3c40907ebf..aa5607430c 100644
--- a/modules/signals/entities/src/helpers.ts
+++ b/modules/signals/entities/src/helpers.ts
@@ -7,7 +7,6 @@ import {
   SelectEntityId,
 } from './models';
 
-declare const ngDevMode: unknown;
 const defaultSelectId: SelectEntityId<{ id: EntityId }> = (entity) => entity.id;
 
 export function getEntityIdSelector(config?: {
diff --git a/modules/signals/events/src/events-service.ts b/modules/signals/events/src/events-service.ts
index f9ce5fd216..0e8779aca0 100644
--- a/modules/signals/events/src/events-service.ts
+++ b/modules/signals/events/src/events-service.ts
@@ -9,8 +9,12 @@ import {
 import { EventInstance } from './event-instance';
 import { EventCreator } from './event-creator';
 
-export const EVENTS = Symbol();
-export const SOURCE_TYPE = Symbol();
+export const EVENTS = Symbol(
+  typeof ngDevMode !== 'undefined' && ngDevMode ? 'EVENTS' : ''
+);
+export const SOURCE_TYPE = Symbol(
+  typeof ngDevMode !== 'undefined' && ngDevMode ? 'SOURCE_TYPE' : ''
+);
 
 abstract class BaseEvents {
   /**
diff --git a/modules/signals/rxjs-interop/src/rx-method.ts b/modules/signals/rxjs-interop/src/rx-method.ts
index 466dd55bd6..eb19d4c39f 100644
--- a/modules/signals/rxjs-interop/src/rx-method.ts
+++ b/modules/signals/rxjs-interop/src/rx-method.ts
@@ -10,8 +10,6 @@ import {
 } from '@angular/core';
 import { isObservable, noop, Observable, Subject } from 'rxjs';
 
-declare const ngDevMode: unknown;
-
 type RxMethodRef = {
   destroy: () => void;
 };
diff --git a/modules/signals/src/deep-signal.ts b/modules/signals/src/deep-signal.ts
index 539673b3f5..3b1098f872 100644
--- a/modules/signals/src/deep-signal.ts
+++ b/modules/signals/src/deep-signal.ts
@@ -1,7 +1,9 @@
 import { computed, isSignal, Signal, untracked } from '@angular/core';
 import { IsKnownRecord } from './ts-helpers';
 
-const DEEP_SIGNAL = Symbol('DEEP_SIGNAL');
+const DEEP_SIGNAL = Symbol(
+  typeof ngDevMode !== 'undefined' && ngDevMode ? 'DEEP_SIGNAL' : ''
+);
 
 export type DeepSignal<T> = Signal<T> &
   (IsKnownRecord<T> extends true
diff --git a/modules/signals/src/signal-method.ts b/modules/signals/src/signal-method.ts
index ae1a9c4b48..24608d30aa 100644
--- a/modules/signals/src/signal-method.ts
+++ b/modules/signals/src/signal-method.ts
@@ -10,8 +10,6 @@ import {
   untracked,
 } from '@angular/core';
 
-declare const ngDevMode: unknown;
-
 export type SignalMethod<Input> = ((
   input: Input | Signal<Input>,
   config?: { injector?: Injector }
diff --git a/modules/signals/src/state-source.ts b/modules/signals/src/state-source.ts
index 6a50fcd796..db60825956 100644
--- a/modules/signals/src/state-source.ts
+++ b/modules/signals/src/state-source.ts
@@ -9,11 +9,11 @@ import {
   WritableSignal,
 } from '@angular/core';
 
-declare const ngDevMode: unknown;
-
 const STATE_WATCHERS = new WeakMap<object, Array<StateWatcher<any>>>();
 
-export const STATE_SOURCE = Symbol('STATE_SOURCE');
+export const STATE_SOURCE = Symbol(
+  typeof ngDevMode !== 'undefined' && ngDevMode ? 'STATE_SOURCE' : ''
+);
 
 export type WritableStateSource<State extends object> = {
   [STATE_SOURCE]: { [K in keyof State]: WritableSignal<State[K]> };