diff --git a/README.md b/README.md
index a88ab91..f5020aa 100644
--- a/README.md
+++ b/README.md
@@ -208,7 +208,6 @@ Curl::getInfo($opt = null)
 Curl::getOpt($option)
 Curl::getResponseCookie($key)
 Curl::head($url, $data = array())
-Curl::headerCallback($ch, $header)
 Curl::options($url, $data = array())
 Curl::patch($url, $data = array())
 Curl::post($url, $data = array(), $follow_303_with_post = false)
diff --git a/src/Curl/Curl.php b/src/Curl/Curl.php
index 11c4d35..c11cc37 100644
--- a/src/Curl/Curl.php
+++ b/src/Curl/Curl.php
@@ -264,41 +264,6 @@ class Curl
         return $this->exec();
     }
 
-    /**
-     * Download Complete
-     *
-     * @access private
-     * @param  $fh
-     */
-    private function downloadComplete($fh)
-    {
-        if (!$this->error && $this->downloadCompleteFunction) {
-            rewind($fh);
-            $this->call($this->downloadCompleteFunction, $fh);
-            $this->downloadCompleteFunction = null;
-        }
-
-        if (is_resource($fh)) {
-            fclose($fh);
-        }
-
-        // Fix "PHP Notice: Use of undefined constant STDOUT" when reading the
-        // PHP script from stdin. Using null causes "Warning: curl_setopt():
-        // supplied argument is not a valid File-Handle resource".
-        if (!defined('STDOUT')) {
-            define('STDOUT', fopen('php://stdout', 'w'));
-        }
-
-        // Reset CURLOPT_FILE with STDOUT to avoid: "curl_exec(): CURLOPT_FILE
-        // resource has gone away, resetting to default".
-        $this->setOpt(CURLOPT_FILE, STDOUT);
-
-        // Reset CURLOPT_RETURNTRANSFER to tell cURL to return subsequent
-        // responses as the return value of curl_exec(). Without this,
-        // curl_exec() will revert to returning boolean values.
-        $this->setOpt(CURLOPT_RETURNTRANSFER, true);
-    }
-
     /**
      * Download
      *
@@ -503,25 +468,6 @@ class Curl
         return $this->exec();
     }
 
-    /**
-     * Create Header Callback
-     *
-     * @access private
-     * @param  $header_callback_data
-     *
-     * @return callable
-     */
-    private function createHeaderCallback($header_callback_data)
-    {
-        return function ($ch, $header) use ($header_callback_data) {
-            if (preg_match('/^Set-Cookie:\s*([^=]+)=([^;]+)/mi', $header, $cookie) === 1) {
-                $header_callback_data->responseCookies[$cookie[1]] = trim($cookie[2], " \n\r\t\0\x0B");
-            }
-            $header_callback_data->rawResponseHeaders .= $header;
-            return strlen($header);
-        };
-    }
-
     /**
      * Options
      *
@@ -1080,7 +1026,7 @@ class Curl
     public function setUrl($url, $mixed_data = '')
     {
         $this->baseUrl = $url;
-        $this->url = $this->buildURL($url, $mixed_data);
+        $this->url = $this->buildUrl($url, $mixed_data);
         $this->setOpt(CURLOPT_URL, $this->url);
     }
 
@@ -1238,7 +1184,7 @@ class Curl
      *
      * @return string
      */
-    private function buildURL($url, $mixed_data = '')
+    private function buildUrl($url, $mixed_data = '')
     {
         $query_string = '';
         if (!empty($mixed_data)) {
@@ -1251,6 +1197,60 @@ class Curl
         return $url . $query_string;
     }
 
+    /**
+     * Create Header Callback
+     *
+     * @access private
+     * @param  $header_callback_data
+     *
+     * @return callable
+     */
+    private function createHeaderCallback($header_callback_data)
+    {
+        return function ($ch, $header) use ($header_callback_data) {
+            if (preg_match('/^Set-Cookie:\s*([^=]+)=([^;]+)/mi', $header, $cookie) === 1) {
+                $header_callback_data->responseCookies[$cookie[1]] = trim($cookie[2], " \n\r\t\0\x0B");
+            }
+            $header_callback_data->rawResponseHeaders .= $header;
+            return strlen($header);
+        };
+    }
+
+    /**
+     * Download Complete
+     *
+     * @access private
+     * @param  $fh
+     */
+    private function downloadComplete($fh)
+    {
+        if (!$this->error && $this->downloadCompleteFunction) {
+            rewind($fh);
+            $this->call($this->downloadCompleteFunction, $fh);
+            $this->downloadCompleteFunction = null;
+        }
+
+        if (is_resource($fh)) {
+            fclose($fh);
+        }
+
+        // Fix "PHP Notice: Use of undefined constant STDOUT" when reading the
+        // PHP script from stdin. Using null causes "Warning: curl_setopt():
+        // supplied argument is not a valid File-Handle resource".
+        if (!defined('STDOUT')) {
+            define('STDOUT', fopen('php://stdout', 'w'));
+        }
+
+        // Reset CURLOPT_FILE with STDOUT to avoid: "curl_exec(): CURLOPT_FILE
+        // resource has gone away, resetting to default".
+        $this->setOpt(CURLOPT_FILE, STDOUT);
+
+        // Reset CURLOPT_RETURNTRANSFER to tell cURL to return subsequent
+        // responses as the return value of curl_exec(). Without this,
+        // curl_exec() will revert to returning boolean values.
+        $this->setOpt(CURLOPT_RETURNTRANSFER, true);
+    }
+
     /**
      * Parse Headers
      *
diff --git a/tests/PHPCurlClass/PHPCurlClassTest.php b/tests/PHPCurlClass/PHPCurlClassTest.php
index 10a24d3..f4f4c4a 100644
--- a/tests/PHPCurlClass/PHPCurlClassTest.php
+++ b/tests/PHPCurlClass/PHPCurlClassTest.php
@@ -3124,7 +3124,7 @@ class CurlTest extends \PHPUnit\Framework\TestCase
         foreach ($tests as $test) {
             $curl_1 = new Curl();
             $reflector = new \ReflectionObject($curl_1);
-            $method = $reflector->getMethod('buildURL');
+            $method = $reflector->getMethod('buildUrl');
             $method->setAccessible(true);
             $actual_url = $method->invoke($curl_1, $test['args']['url'], $test['args']['mixed_data']);
             $this->assertEquals($test['expected'], $actual_url);
@@ -3152,7 +3152,7 @@ class CurlTest extends \PHPUnit\Framework\TestCase
             $curl = new Curl();
 
             $reflector = new \ReflectionObject($curl);
-            $method = $reflector->getMethod('buildURL');
+            $method = $reflector->getMethod('buildUrl');
             $method->setAccessible(true);
 
             $actual_url = $method->invoke($curl, $base_url, $data);