diff --git a/FirebaseVertexAI/CHANGELOG.md b/FirebaseVertexAI/CHANGELOG.md
index f3d471969c3..21271329704 100644
--- a/FirebaseVertexAI/CHANGELOG.md
+++ b/FirebaseVertexAI/CHANGELOG.md
@@ -22,6 +22,9 @@
   is now optional (`Int?`); it may be `null` in cases such as when a
   `GenerateContentRequest` contains only images or other non-text content.
   (#13721)
+- [changed] The default request timeout is now 180 seconds instead of the
+  platform-default value of 60 seconds for a `URLRequest`; this timeout may
+  still be customized in `RequestOptions`. (#13722)
 
 # 11.3.0
 - [added] Added `Decodable` conformance for `FunctionResponse`. (#13606)
diff --git a/FirebaseVertexAI/Sources/GenerativeAIRequest.swift b/FirebaseVertexAI/Sources/GenerativeAIRequest.swift
index 08b178d5808..55f7af7d1be 100644
--- a/FirebaseVertexAI/Sources/GenerativeAIRequest.swift
+++ b/FirebaseVertexAI/Sources/GenerativeAIRequest.swift
@@ -28,7 +28,7 @@ protocol GenerativeAIRequest: Encodable {
 public struct RequestOptions {
   /// The request’s timeout interval in seconds; if not specified uses the default value for a
   /// `URLRequest`.
-  let timeout: TimeInterval?
+  let timeout: TimeInterval
 
   /// The API version to use in requests to the backend.
   let apiVersion = "v2beta"
@@ -36,9 +36,8 @@ public struct RequestOptions {
   /// Initializes a request options object.
   ///
   /// - Parameters:
-  ///   - timeout The request’s timeout interval in seconds; if not specified uses the default value
-  ///   for a `URLRequest`.
-  public init(timeout: TimeInterval? = nil) {
+  ///   - timeout The request’s timeout interval in seconds; defaults to 180 seconds.
+  public init(timeout: TimeInterval = 180.0) {
     self.timeout = timeout
   }
 }
diff --git a/FirebaseVertexAI/Sources/GenerativeAIService.swift b/FirebaseVertexAI/Sources/GenerativeAIService.swift
index 3ebbf69f102..36a208440fb 100644
--- a/FirebaseVertexAI/Sources/GenerativeAIService.swift
+++ b/FirebaseVertexAI/Sources/GenerativeAIService.swift
@@ -191,10 +191,7 @@ struct GenerativeAIService {
     let encoder = JSONEncoder()
     encoder.keyEncodingStrategy = .convertToSnakeCase
     urlRequest.httpBody = try encoder.encode(request)
-
-    if let timeoutInterval = request.options.timeout {
-      urlRequest.timeoutInterval = timeoutInterval
-    }
+    urlRequest.timeoutInterval = request.options.timeout
 
     return urlRequest
   }
diff --git a/FirebaseVertexAI/Tests/Unit/GenerativeModelTests.swift b/FirebaseVertexAI/Tests/Unit/GenerativeModelTests.swift
index c7cfe36df70..0dc352291b2 100644
--- a/FirebaseVertexAI/Tests/Unit/GenerativeModelTests.swift
+++ b/FirebaseVertexAI/Tests/Unit/GenerativeModelTests.swift
@@ -1267,7 +1267,7 @@ final class GenerativeModelTests: XCTestCase {
   private func httpRequestHandler(forResource name: String,
                                   withExtension ext: String,
                                   statusCode: Int = 200,
-                                  timeout: TimeInterval = URLRequest.defaultTimeoutInterval(),
+                                  timeout: TimeInterval = RequestOptions().timeout,
                                   appCheckToken: String? = nil,
                                   authToken: String? = nil) throws -> ((URLRequest) throws -> (
     URLResponse,
@@ -1316,14 +1316,6 @@ private extension String {
   }
 }
 
-private extension URLRequest {
-  /// Returns the default `timeoutInterval` for a `URLRequest`.
-  static func defaultTimeoutInterval() -> TimeInterval {
-    let placeholderURL = URL(string: "https://example.com")!
-    return URLRequest(url: placeholderURL).timeoutInterval
-  }
-}
-
 @available(iOS 15.0, macOS 12.0, macCatalyst 15.0, tvOS 15.0, watchOS 8.0, *)
 class AppCheckInteropFake: NSObject, AppCheckInterop {
   /// The placeholder token value returned when an error occurs