diff --git a/AlamofireObjectMapper.podspec b/AlamofireObjectMapper.podspec
index 08c215e..6e85429 100644
--- a/AlamofireObjectMapper.podspec
+++ b/AlamofireObjectMapper.podspec
@@ -17,6 +17,6 @@ Pod::Spec.new do |s|
 
   s.requires_arc = true
   s.source_files = 'AlamofireObjectMapper/**/*.swift'
-  s.dependency 'Alamofire', '~> 5.0.0-beta.2'
+  s.dependency 'Alamofire', '5.0.0-beta.6'
   s.dependency 'ObjectMapper', '~> 3.4'
 end
diff --git a/AlamofireObjectMapper/AlamofireObjectMapper.swift b/AlamofireObjectMapper/AlamofireObjectMapper.swift
index bc78327..6dc539b 100644
--- a/AlamofireObjectMapper/AlamofireObjectMapper.swift
+++ b/AlamofireObjectMapper/AlamofireObjectMapper.swift
@@ -129,12 +129,12 @@ extension DataRequest {
      - returns: The request.
      */
     @discardableResult
-    public func responseObject<T: BaseMappable>(queue: DispatchQueue? = nil, keyPath: String? = nil, mapToObject object: T? = nil, context: MapContext? = nil, completionHandler: @escaping (DataResponse<T>) -> Void) -> Self {
+    public func responseObject<T: BaseMappable>(queue: DispatchQueue = .main, keyPath: String? = nil, mapToObject object: T? = nil, context: MapContext? = nil, completionHandler: @escaping (DataResponse<T>) -> Void) -> Self {
         return response(queue: queue, responseSerializer: DataRequest.ObjectMapperSerializer(keyPath, mapToObject: object, context: context), completionHandler: completionHandler)
     }
     
     @discardableResult
-    public func responseObject<T: ImmutableMappable>(queue: DispatchQueue? = nil, keyPath: String? = nil, mapToObject object: T? = nil, context: MapContext? = nil, completionHandler: @escaping (DataResponse<T>) -> Void) -> Self {
+    public func responseObject<T: ImmutableMappable>(queue: DispatchQueue = .main, keyPath: String? = nil, mapToObject object: T? = nil, context: MapContext? = nil, completionHandler: @escaping (DataResponse<T>) -> Void) -> Self {
         return response(queue: queue, responseSerializer: DataRequest.ObjectMapperImmutableSerializer(keyPath, context: context), completionHandler: completionHandler)
     }
     
@@ -185,7 +185,7 @@ extension DataRequest {
      - returns: The request.
      */
     @discardableResult
-    public func responseArray<T: BaseMappable>(queue: DispatchQueue? = nil, keyPath: String? = nil, context: MapContext? = nil, completionHandler: @escaping (DataResponse<[T]>) -> Void) -> Self {
+    public func responseArray<T: BaseMappable>(queue: DispatchQueue = .main, keyPath: String? = nil, context: MapContext? = nil, completionHandler: @escaping (DataResponse<[T]>) -> Void) -> Self {
         return response(queue: queue, responseSerializer: DataRequest.ObjectMapperArraySerializer(keyPath, context: context), completionHandler: completionHandler)
     }
     
@@ -199,7 +199,7 @@ extension DataRequest {
      - returns: The request.
      */
     @discardableResult
-    public func responseArray<T: ImmutableMappable>(queue: DispatchQueue? = nil, keyPath: String? = nil, context: MapContext? = nil, completionHandler: @escaping (DataResponse<[T]>) -> Void) -> Self {
+    public func responseArray<T: ImmutableMappable>(queue: DispatchQueue = .main, keyPath: String? = nil, context: MapContext? = nil, completionHandler: @escaping (DataResponse<[T]>) -> Void) -> Self {
         return response(queue: queue, responseSerializer: DataRequest.ObjectMapperImmutableArraySerializer(keyPath, context: context), completionHandler: completionHandler)
     }
 }