     internal func clientURLRequest(_ path: String, query: [String: Queryable]?, params: ValidRequestData?)
         -> URLRequest {
             var request = URLRequest(url: URL(string: baseURL + path, query: query))
-            if let params = params {
-                let jsonData = try? params.requestData()
-                request.httpBody = jsonData
+            if let params = params, let httpData = try? params.requestData() {
+                request.httpBody = httpData
+                request.addValue(String(httpData.count), forHTTPHeaderField: "Content-Length")
             }
             
             headers.forEach() {

public enum ContentType {
    case json
    case formEncoded
}

/// Converting to JSON error type

            return "application/json"
        case .formEncoded:
            return "application/x-www-form-urlencoded"
        case let .custom(format):
            return format
        }
    }
}
