diff --git a/lib/SimpleSAML/Utilities.php b/lib/SimpleSAML/Utilities.php
index b1d37a739046ca00c6b7dc204d202e4a7ec4afc4..d40f28587fda62047331764f1e1299531508ebfb 100644
--- a/lib/SimpleSAML/Utilities.php
+++ b/lib/SimpleSAML/Utilities.php
@@ -690,6 +690,11 @@ class SimpleSAML_Utilities {
 			/* Encode the parameter. */
 			if($value === NULL) {
 				$param = urlencode($name);
+			} elseif (is_array($value)) {
+				$param = "";
+				foreach ($value as $val) {
+					$param .= urlencode($name) . "[]=" . urlencode($val) . '&';				
+				}
 			} else {
 				$param = urlencode($name) . '=' .
 					urlencode($value);