diff --git a/core/modules/rdf/rdf.module b/core/modules/rdf/rdf.module
index fce7f1cce9a19738d7b9fd4d40645b52d2c98453..4cc462c4560eed73aa35557d832d81fa587c0386 100644
--- a/core/modules/rdf/rdf.module
+++ b/core/modules/rdf/rdf.module
@@ -254,7 +254,6 @@ function rdf_theme() {
 function rdf_preprocess_html(&$variables) {
   // Adds RDF namespace prefix bindings in the form of an RDFa 1.1 prefix
   // attribute inside the html element.
-  $prefixes = array();
   if (!isset($variables['html_attributes']['prefix'])) {
     $variables['html_attributes']['prefix'] = array();
   }