diff --git a/module/VuFind/src/VuFind/ILS/Driver/MultiBackend.php b/module/VuFind/src/VuFind/ILS/Driver/MultiBackend.php
index 64f4aa68b4eb7aa00ed75c93858fd713601bd2d0..4a7eff60e7bc7659e55cb9d066190568dfbb76f0 100644
--- a/module/VuFind/src/VuFind/ILS/Driver/MultiBackend.php
+++ b/module/VuFind/src/VuFind/ILS/Driver/MultiBackend.php
@@ -392,15 +392,13 @@ class MultiBackend extends AbstractBase
     protected function addIdPrefixes($data, $source,
         $modifyFields = array('id', 'cat_username')
     ) {
-
-        if (!isset($data) || empty($data) ) {
+        if (!isset($data) || empty($data) || !is_array($data)) {
             return $data;
         }
-        $array = is_array($data) ? $data : array($data);
 
-        foreach ($array as $key => $value) {
+        foreach ($data as $key => $value) {
             if (is_array($value)) {
-                $array[$key] = $this->addIdPrefixes(
+                $data[$key] = $this->addIdPrefixes(
                     $value, $source, $modifyFields
                 );
             } else {
@@ -408,11 +406,11 @@ class MultiBackend extends AbstractBase
                     && $value !== ''
                     && in_array($key, $modifyFields)
                 ) {
-                    $array[$key] = $source . '.' . $value;
+                    $data[$key] = $source . '.' . $value;
                 }
             }
         }
-        return is_array($data) ? $array : $array[0];
+        return $data;
     }
 
     /**
diff --git a/module/VuFind/tests/unit-tests/src/VuFindTest/ILS/Driver/MultiBackendTest.php b/module/VuFind/tests/unit-tests/src/VuFindTest/ILS/Driver/MultiBackendTest.php
index 15028d396e2d47d24c051e2488cc456f090b7f3a..4bbdf2981af4f8a13b91f34d4bf8087d5e6c5428 100644
--- a/module/VuFind/tests/unit-tests/src/VuFindTest/ILS/Driver/MultiBackendTest.php
+++ b/module/VuFind/tests/unit-tests/src/VuFindTest/ILS/Driver/MultiBackendTest.php
@@ -681,12 +681,6 @@ class MultiBackendTest extends \VuFindTest\Unit\TestCase
         $result = $this->callMethod($driver, 'addIdPrefixes', array($data, $source));
         $this->assertEquals($data, $result);
 
-        /* test disabled 3/19/2014 -- do we really want to prefix non-array strings?
-        $data = "record";
-        $result = $this->callMethod($driver, 'addIdPrefixes', array($data, $source));
-        $this->assertEquals("$source.$data", $result);
-         */
-
         $data = array(
             "id" => "record1",
             "cat_username" => "record2"