diff --git a/src/GoTrueClient.ts b/src/GoTrueClient.ts
index 7fa4a9741..adaad53ab 100644
--- a/src/GoTrueClient.ts
+++ b/src/GoTrueClient.ts
@@ -30,7 +30,7 @@ import {
   supportsLocalStorage,
   parseParametersFromURL,
 } from './lib/helpers'
-import localStorageAdapter from './lib/local-storage'
+import { localStorageAdapter, memoryLocalStorageAdapter } from './lib/local-storage'
 import { polyfillGlobalThis } from './lib/polyfills'
 import { version } from './lib/version'
 import { LockAcquireTimeoutError } from './lib/locks'
@@ -123,17 +123,12 @@ export default class GoTrueClient {
    */
   protected storageKey: string
 
-  /**
-   * The session object for the currently logged in user. If null, it means there isn't a logged-in user.
-   * Only used if persistSession is false.
-   */
-  protected inMemorySession: Session | null
-
   protected flowType: AuthFlowType
 
   protected autoRefreshToken: boolean
   protected persistSession: boolean
   protected storage: SupportedStorage
+  protected memoryStorage: { [key: string]: string } | null = null
   protected stateChangeEmitters: Map<string, Subscription> = new Map()
   protected autoRefreshTicker: ReturnType<typeof setInterval> | null = null
   protected visibilityChangedCallback: (() => Promise<any>) | null = null
@@ -183,11 +178,9 @@ export default class GoTrueClient {
       this.logger = settings.debug
     }
 
-    this.inMemorySession = null
+    this.persistSession = settings.persistSession
     this.storageKey = settings.storageKey
     this.autoRefreshToken = settings.autoRefreshToken
-    this.persistSession = settings.persistSession
-    this.storage = settings.storage || localStorageAdapter
     this.admin = new GoTrueAdminApi({
       url: settings.url,
       headers: settings.headers,
@@ -211,11 +204,20 @@ export default class GoTrueClient {
       getAuthenticatorAssuranceLevel: this._getAuthenticatorAssuranceLevel.bind(this),
     }
 
-    if (this.persistSession && this.storage === localStorageAdapter && !supportsLocalStorage()) {
-      console.warn(
-        `No storage option exists to persist the session, which may result in unexpected behavior when using auth.
-        If you want to set persistSession to true, please provide a storage option or you may set persistSession to false to disable this warning.`
-      )
+    if (this.persistSession) {
+      if (settings.storage) {
+        this.storage = settings.storage
+      } else {
+        if (supportsLocalStorage()) {
+          this.storage = localStorageAdapter
+        } else {
+          this.memoryStorage = {}
+          this.storage = memoryLocalStorageAdapter(this.memoryStorage)
+        }
+      }
+    } else {
+      this.memoryStorage = {}
+      this.storage = memoryLocalStorageAdapter(this.memoryStorage)
     }
 
     if (isBrowser() && globalThis.BroadcastChannel && this.persistSession && this.storageKey) {
@@ -970,22 +972,17 @@ export default class GoTrueClient {
     try {
       let currentSession: Session | null = null
 
-      if (this.persistSession) {
-        const maybeSession = await getItemAsync(this.storage, this.storageKey)
+      const maybeSession = await getItemAsync(this.storage, this.storageKey)
 
-        this._debug('#getSession()', 'session from storage', maybeSession)
+      this._debug('#getSession()', 'session from storage', maybeSession)
 
-        if (maybeSession !== null) {
-          if (this._isValidSession(maybeSession)) {
-            currentSession = maybeSession
-          } else {
-            this._debug('#getSession()', 'session from storage is not valid')
-            await this._removeSession()
-          }
+      if (maybeSession !== null) {
+        if (this._isValidSession(maybeSession)) {
+          currentSession = maybeSession
+        } else {
+          this._debug('#getSession()', 'session from storage is not valid')
+          await this._removeSession()
         }
-      } else {
-        currentSession = this.inMemorySession
-        this._debug('#getSession()', 'session from memory', currentSession)
       }
 
       if (!currentSession) {
@@ -1787,13 +1784,7 @@ export default class GoTrueClient {
   private async _saveSession(session: Session) {
     this._debug('#_saveSession()', session)
 
-    if (!this.persistSession) {
-      this.inMemorySession = session
-    }
-
-    if (this.persistSession && session.expires_at) {
-      await this._persistSession(session)
-    }
+    await this._persistSession(session)
   }
 
   private _persistSession(currentSession: Session) {
@@ -1805,11 +1796,7 @@ export default class GoTrueClient {
   private async _removeSession() {
     this._debug('#_removeSession()')
 
-    if (this.persistSession) {
-      await removeItemAsync(this.storage, this.storageKey)
-    } else {
-      this.inMemorySession = null
-    }
+    await removeItemAsync(this.storage, this.storageKey)
   }
 
   /**
diff --git a/src/lib/local-storage.ts b/src/lib/local-storage.ts
index ceea1aed1..d103f5649 100644
--- a/src/lib/local-storage.ts
+++ b/src/lib/local-storage.ts
@@ -1,7 +1,10 @@
 import { supportsLocalStorage } from './helpers'
 import { SupportedStorage } from './types'
 
-const localStorageAdapter: SupportedStorage = {
+/**
+ * Provides safe access to the globalThis.localStorage property.
+ */
+export const localStorageAdapter: SupportedStorage = {
   getItem: (key) => {
     if (!supportsLocalStorage()) {
       return null
@@ -25,4 +28,22 @@ const localStorageAdapter: SupportedStorage = {
   },
 }
 
-export default localStorageAdapter
+/**
+ * Returns a localStorage-like object that stores the key-value pairs in
+ * memory.
+ */
+export function memoryLocalStorageAdapter(store: { [key: string]: string } = {}): SupportedStorage {
+  return {
+    getItem: (key) => {
+      return store[key] || null
+    },
+
+    setItem: (key, value) => {
+      store[key] = value
+    },
+
+    removeItem: (key) => {
+      delete store[key]
+    },
+  }
+}
diff --git a/test/GoTrueClient.test.ts b/test/GoTrueClient.test.ts
index 86d0e539f..b2ae4efd8 100644
--- a/test/GoTrueClient.test.ts
+++ b/test/GoTrueClient.test.ts
@@ -177,12 +177,19 @@ describe('GoTrueClient', () => {
       expired.setMinutes(expired.getMinutes() - 1)
       const expiredSeconds = Math.floor(expired.getTime() / 1000)
 
-      // @ts-expect-error 'Allow access to protected inMemorySession'
-      authWithSession.inMemorySession = {
-        // @ts-expect-error 'Allow access to protected inMemorySession'
-        ...authWithSession.inMemorySession,
-        expires_at: expiredSeconds,
-      }
+      // @ts-expect-error 'Allow access to protected storage'
+      const storage = authWithSession.storage
+
+      // @ts-expect-error 'Allow access to protected storageKey'
+      const storageKey = authWithSession.storageKey
+
+      await storage.setItem(
+        storageKey,
+        JSON.stringify({
+          ...JSON.parse((await storage.getItem(storageKey)) || 'null'),
+          expires_at: expiredSeconds,
+        })
+      )
 
       // wait 1 seconds before calling getSession()
       await new Promise((r) => setTimeout(r, 1000))
diff --git a/test/lib/clients.ts b/test/lib/clients.ts
index 7295f810e..e042b7212 100644
--- a/test/lib/clients.ts
+++ b/test/lib/clients.ts
@@ -46,7 +46,8 @@ export const authClient = new GoTrueClient({
 export const authClientWithSession = new GoTrueClient({
   url: GOTRUE_URL_SIGNUP_ENABLED_AUTO_CONFIRM_ON,
   autoRefreshToken: false,
-  persistSession: false,
+  persistSession: true,
+  storage: new MemoryStorage(),
 })
 
 export const authSubscriptionClient = new GoTrueClient({