diff --git a/plugins/facetapi/widget.inc b/plugins/facetapi/widget.inc
index 7eb02cc..8acdf23 100644
--- a/plugins/facetapi/widget.inc
+++ b/plugins/facetapi/widget.inc
@@ -90,7 +90,7 @@ abstract class FacetapiWidget {
   public function init() {
 
     // Captures searcher for code readability.
-    $searcher = $this->facet->getAdapter()->getSearcher();
+    $searcher = preg_replace('/[^\x{002D}\x{0030}-\x{0039}\x{0041}-\x{005A}\x{005F}\x{0061}-\x{007A}\x{00A1}-\x{FFFF}]/u', '', $this->facet->getAdapter()->getSearcher());
 
     $classes = implode(' ', array("facetapi-" . $this->id, "facetapi-facet-{$this->facet['name']}"));