diff --git a/modal_forms.module b/modal_forms.module
index 8c4645d..7348ca2 100644
--- a/modal_forms.module
+++ b/modal_forms.module
@@ -249,9 +249,20 @@ function _modal_forms_doheader() {
   drupal_add_js($js_settings, 'setting');
 
   // Add modal_forms own js and CSS.
-  ctools_add_css('modal_forms_popup', 'modal_forms');
   ctools_add_js('modal_forms_popup', 'modal_forms');
 
+  // Allowing default modal_forms_popup overriding
+  // Search for modal_forms_popup.css file in current theme folder
+  $pattern = '/modal_forms_popup\.css$/';
+  $themes = list_themes();
+
+  $files = file_scan_directory(drupal_get_path('theme', $themes[$GLOBALS['theme']]->name), $pattern);
+  if (empty($files)) {
+    ctools_add_css('modal_forms_popup', 'modal_forms');
+  } else {
+    drupal_add_css(reset($files)->uri);
+  }
+
   $path = drupal_get_path('module', 'modal_forms');
 
   // Automatically rewrite selected links to open in a modal.