diff --git a/.scrutinizer.yml b/.scrutinizer.yml
index 67c425e2a..dd2b8cd57 100644
--- a/.scrutinizer.yml
+++ b/.scrutinizer.yml
@@ -3,3 +3,5 @@ tools:
         -
             scope: file
             command: php tests/phpcs_runner.php %pathname%
+            filter:
+               excluded_paths: ["*/css/*", "css/*", "thirdparty/*", "*/jquery-changetracker/*", "parsers/HTML/BBCodeParser/*", "*/SSTemplateParser.php$"]
diff --git a/tests/phpcs_runner.php b/tests/phpcs_runner.php
index 43a53dc00..602377e8c 100644
--- a/tests/phpcs_runner.php
+++ b/tests/phpcs_runner.php
@@ -12,14 +12,18 @@ if(!empty($_SERVER['argv'][1])) {
 
 $result = array('comments' => array());
 
-// Run each sniff
+$extension = pathinfo($path, PATHINFO_EXTENSION);
 
-// phpcs --encoding=utf-8 --standard=framework/tests/phpcs/tabs.xml
-run_sniff('tabs.xml', $path, $result);
+// Whitelist of extensions to check (default phpcs list)
+if(in_array($extension, array('php', 'js', 'inc', 'css'))) {
+	// Run each sniff
 
-// phpcs --encoding=utf-8 --tab-width=4 --standard=framework/tests/phpcs/ruleset.xml
-run_sniff('ruleset.xml', $path, $result, '--tab-width=4');
+	// phpcs --encoding=utf-8 --standard=framework/tests/phpcs/tabs.xml
+	run_sniff('tabs.xml', $path, $result);
 
+	// phpcs --encoding=utf-8 --tab-width=4 --standard=framework/tests/phpcs/ruleset.xml
+	run_sniff('ruleset.xml', $path, $result, '--tab-width=4');
+}
 echo json_encode($result);
 
 function run_sniff($standard, $path, array &$result, $extraFlags = '') {