diff --git a/Swifter/Dictionary+Swifter.swift b/Swifter/Dictionary+Swifter.swift
index 34fba119..119e8cfd 100644
--- a/Swifter/Dictionary+Swifter.swift
+++ b/Swifter/Dictionary+Swifter.swift
@@ -62,9 +62,9 @@ extension Dictionary {
     }
     
     func stringifiedDictionary() -> Dictionary<String, String> {
-        let dict = self.reduce([String: String]()) { (var dict, tuple) in
-            dict["\(tuple.0)"] = "\(tuple.1)"
-            return dict
+        var dict = [String: String]()
+        for (key, value) in self {
+            dict[String(key)] = String(value)
         }
         return dict
     }
diff --git a/Swifter/SwifterOAuthClient.swift b/Swifter/SwifterOAuthClient.swift
index e7107c1e..42b6a214 100644
--- a/Swifter/SwifterOAuthClient.swift
+++ b/Swifter/SwifterOAuthClient.swift
@@ -70,9 +70,9 @@ internal class SwifterOAuthClient: SwifterClientProtocol  {
         return request
     }
 
-    func post(path: String, baseURL: NSURL, var parameters: Dictionary<String, Any>, uploadProgress: SwifterHTTPRequest.UploadProgressHandler?, downloadProgress: SwifterHTTPRequest.DownloadProgressHandler?, success: SwifterHTTPRequest.SuccessHandler?, failure: SwifterHTTPRequest.FailureHandler?) -> SwifterHTTPRequest {
+    func post(path: String, baseURL: NSURL, parameters: Dictionary<String, Any>, uploadProgress: SwifterHTTPRequest.UploadProgressHandler?, downloadProgress: SwifterHTTPRequest.DownloadProgressHandler?, success: SwifterHTTPRequest.SuccessHandler?, failure: SwifterHTTPRequest.FailureHandler?) -> SwifterHTTPRequest {
         let url = NSURL(string: path, relativeToURL: baseURL)!
-
+        var parameters = parameters
         var postData: NSData?
         var postDataKey: String?