diff --git a/forms/htmleditor/TinyMCEConfig.php b/forms/htmleditor/TinyMCEConfig.php
index 6cf06fc48..2873f6dbb 100644
--- a/forms/htmleditor/TinyMCEConfig.php
+++ b/forms/htmleditor/TinyMCEConfig.php
@@ -34,6 +34,7 @@ class TinyMCEConfig extends HtmlEditorConfig {
 		'remove_script_host' => true,
 		'convert_urls' => false, // Prevent site-root images being rewritten to base relative
 		'menubar' => false,
+		'language' => 'en',
     );
 
 	/**
@@ -198,6 +199,24 @@ class TinyMCEConfig extends HtmlEditorConfig {
 		return $this->plugins;
 	}
 
+	/**
+	 * Get list of plugins without custom locations, which is the set of
+	 * plugins which can be loaded via the standard plugin path, and could
+	 * potentially be minified
+	 *
+	 * @return array
+	 */
+	public function getInternalPlugins() {
+		// Return only plugins with no custom url
+		$plugins = [];
+		foreach($this->getPlugins() as $name => $url) {
+			if(empty($url)) {
+				$plugins[] = $name;
+			}
+		}
+		return $plugins;
+	}
+
     /**
      * Get all button rows, skipping empty rows
      *
@@ -416,31 +435,26 @@ class TinyMCEConfig extends HtmlEditorConfig {
 	 * Generate gzipped TinyMCE configuration including plugins and languages.
 	 * This ends up "pre-loading" TinyMCE bundled with the required plugins
 	 * so that multiple HTTP requests on the client don't need to be made.
+	 *
+	 * @return string
 	 */
-	public function requireJS() {
-		require_once THIRDPARTY_PATH . '/tinymce/tiny_mce_gzip.php';
-
+	public function getScriptURL() {
+		// If gzip is disabled just return core script url
 		$useGzip = Config::inst()->get('HtmlEditorField', 'use_gzip');
-		$languages = array();
-
-		foreach(self::$configs as $configID => $config) {
-			$languages[] = $config->getOption('language');
+		if(!$useGzip) {
+			return THIRDPARTY_DIR . '/tinymce/tinymce.min.js';
 		}
 
 		// tinyMCE JS requirement
-		if($useGzip) {
-			$tag = TinyMCE_Compressor::renderTag(array(
-				'url' => THIRDPARTY_DIR . '/tinymce/tiny_mce_gzip.php',
-				'plugins' => implode(',', array_keys($this->getPlugins())),
-				'themes' => $this->getTheme(),
-				'languages' => implode(',', array_filter($languages))
-			), true);
-			preg_match('/src="([^"]*)"/', $tag, $matches);
-
-			Requirements::javascript(html_entity_decode($matches[1]));
-		} else {
-			Requirements::javascript(THIRDPARTY_DIR . '/tinymce/tinymce.min.js');
-		}
+		require_once THIRDPARTY_PATH . '/tinymce/tiny_mce_gzip.php';
+		$tag = TinyMCE_Compressor::renderTag(array(
+			'url' => THIRDPARTY_DIR . '/tinymce/tiny_mce_gzip.php',
+			'plugins' => implode(',', $this->getInternalPlugins()),
+			'themes' => $this->getTheme(),
+			'languages' => $this->getOption('language')
+		), true);
+		preg_match('/src="([^"]*)"/', $tag, $matches);
+		return html_entity_decode($matches[1]);
 	}
 
 	public function init() {
@@ -451,7 +465,7 @@ class TinyMCEConfig extends HtmlEditorConfig {
 		Requirements::javascript(FRAMEWORK_ADMIN_DIR . '/javascript/dist/ssui.core.js');
 
 		// include TinyMCE Javascript
-		$this->requireJS();
+		Requirements::javascript($this->getScriptURL());
 		Requirements::javascript(FRAMEWORK_DIR ."/javascript/dist/HtmlEditorField.js");
 
 		Requirements::css(THIRDPARTY_DIR . '/jquery-ui-themes/smoothness/jquery-ui.css');
diff --git a/tests/forms/HtmlEditorConfigTest.php b/tests/forms/HtmlEditorConfigTest.php
index eb5eef7f3..8223b535c 100644
--- a/tests/forms/HtmlEditorConfigTest.php
+++ b/tests/forms/HtmlEditorConfigTest.php
@@ -28,11 +28,15 @@ class HtmlEditorConfigTest extends SapphireTest {
 	public function testEnablePluginsByArrayWithPaths() {
 		Config::inst()->update('Director', 'alternate_base_url', 'http://mysite.com/subdir');
 		$c = new TinyMCEConfig();
+		$c->setTheme('modern');
+		$c->setOption('language', 'es');
+		$c->disablePlugins('table', 'emoticons', 'paste', 'code', 'link', 'importcss');
 		$c->enablePlugins(array(
 			'plugin1' => 'mypath/plugin1.js',
 			'plugin2' => '/anotherbase/mypath/plugin2.js',
 			'plugin3' => 'https://www.google.com/plugin.js',
 			'plugin4' => null,
+			'plugin5' => null,
 		));
 		$attributes = $c->getAttributes();
 		$config = Convert::json2array($attributes['data-config']);
@@ -66,6 +70,23 @@ class HtmlEditorConfigTest extends SapphireTest {
 			'http://mysite.com/subdir/framework/thirdparty/tinymce/plugins/plugin4/plugin.min.js',
 			$plugins['plugin4']
 		);
+
+		// Check that internal plugins are extractable separately
+		$this->assertEquals(['plugin4', 'plugin5'], $c->getInternalPlugins());
+
+		// Test plugins included via gzip compresser
+		Config::inst()->update('HtmlEditorField', 'use_gzip', true);
+		$this->assertEquals(
+			'framework/thirdparty/tinymce/tiny_mce_gzip.php?js=1&plugins=plugin4,plugin5&themes=modern&languages=es&diskcache=true&src=true',
+			$c->getScriptURL()
+		);
+
+		// If gzip is disabled only the core plugin is loaded
+		Config::inst()->remove('HtmlEditorField', 'use_gzip');
+		$this->assertEquals(
+			'framework/thirdparty/tinymce/tinymce.min.js',
+			$c->getScriptURL()
+		);
 	}
 
 	public function testDisablePluginsByString() {