diff --git a/packages/expo/src/client.ts b/packages/expo/src/client.ts
index a87c0109ea..860f56a3ac 100644
--- a/packages/expo/src/client.ts
+++ b/packages/expo/src/client.ts
@@ -396,7 +396,7 @@ export const expoClient = (opts: ExpoClientOptions) => {
 							// Only process and notify if the Set-Cookie header contains better-auth cookies
 							// This prevents infinite refetching when other cookies (like Cloudflare's __cf_bm) are present
 							if (hasBetterAuthCookies(setCookie, cookiePrefix)) {
-								const prevCookie = await storage.getItem(cookieName);
+								const prevCookie = storage.getItem(cookieName);
 								const toSetCookie = getSetCookie(
 									setCookie || "",
 									prevCookie ?? undefined,
@@ -408,7 +408,7 @@ export const expoClient = (opts: ExpoClientOptions) => {
 									store?.notify("$sessionSignal");
 								} else {
 									// Still update the storage to refresh expiry times, but don't trigger refetch
-									await storage.setItem(cookieName, toSetCookie);
+									storage.setItem(cookieName, toSetCookie);
 								}
 							}
 						}
@@ -449,7 +449,7 @@ export const expoClient = (opts: ExpoClientOptions) => {
 								} catch {}
 							}
 
-							const storedCookieJson = await storage.getItem(cookieName);
+							const storedCookieJson = storage.getItem(cookieName);
 							const oauthStateValue = getOAuthStateValue(
 								storedCookieJson,
 								cookiePrefix,
@@ -468,9 +468,9 @@ export const expoClient = (opts: ExpoClientOptions) => {
 							);
 							if (result.type !== "success") return;
 							const url = new URL(result.url);
-							const cookie = String(url.searchParams.get("cookie"));
+							const cookie = url.searchParams.get("cookie");
 							if (!cookie) return;
-							const prevCookie = await storage.getItem(cookieName);
+							const prevCookie = storage.getItem(cookieName);
 							const toSetCookie = getSetCookie(cookie, prevCookie ?? undefined);
 							storage.setItem(cookieName, toSetCookie);
 							store?.notify("$sessionSignal");
@@ -519,7 +519,7 @@ export const expoClient = (opts: ExpoClientOptions) => {
 						}
 					}
 					if (url.includes("/sign-out")) {
-						await storage.setItem(cookieName, "{}");
+						storage.setItem(cookieName, "{}");
 						store?.atoms.session?.set({
 							...store.atoms.session.get(),
 							data: null,
diff --git a/packages/expo/test/expo.test.ts b/packages/expo/test/expo.test.ts
index 3f2b5e8fd6..8a42e77762 100644
--- a/packages/expo/test/expo.test.ts
+++ b/packages/expo/test/expo.test.ts
@@ -427,6 +427,44 @@ describe("expo", async () => {
 		});
 	});
 
+	it("should not corrupt cookies when redirect URL has no cookie param", async () => {
+		await client.signIn.email({
+			email: testUser.email,
+			password: testUser.password,
+		});
+
+		const storedCookieBefore = storage.get("better-auth_cookie");
+		expect(storedCookieBefore).toBeDefined();
+		const parsedCookieBefore = JSON.parse(storedCookieBefore || "");
+		expect(parsedCookieBefore["better-auth.session_token"]).toBeDefined();
+
+		const expoWebBrowser = await import("expo-web-browser");
+
+		vi.mocked(expoWebBrowser.openAuthSessionAsync).mockResolvedValueOnce({
+			type: "success",
+			url: "better-auth:///dashboard", // No cookie param
+		});
+
+		await client.signIn.social({
+			provider: "google",
+			callbackURL: "/dashboard",
+		});
+
+		// Cookies should be preserved, not corrupted with "null" key
+		const storedCookieAfter = storage.get("better-auth_cookie");
+		expect(storedCookieAfter).toBeDefined();
+		const parsedCookieAfter = JSON.parse(storedCookieAfter || "");
+
+		// Should NOT have "null" as a cookie key
+		expect(parsedCookieAfter["null"]).toBeUndefined();
+
+		// Original session_token should still exist
+		expect(parsedCookieAfter["better-auth.session_token"]).toBeDefined();
+		expect(parsedCookieAfter["better-auth.session_token"]?.value).toBe(
+			parsedCookieBefore["better-auth.session_token"]?.value,
+		);
+	});
+
 	it("should NOT include oauthState param in proxy URL when using database strategy", async () => {
 		fn.mockClear();