diff --git a/includes/derivatives.inc b/includes/derivatives.inc
index 9b44b9af..085a1ec6 100644
--- a/includes/derivatives.inc
+++ b/includes/derivatives.inc
@@ -306,6 +306,6 @@ function islandora_get_derivative_list(AbstractObject $object, &$options) {
     drupal_alter($hook, $derivatives, $object, $ds_modified_params);
   }
 
-  uasort($derivatives, 'drupal_sort_weight');
+  islandora_sort_ordered($derivatives, array('weight'));
   return islandora_filter_derivatives($derivatives, $options, $object);
 }
diff --git a/includes/ingest.form.inc b/includes/ingest.form.inc
index 7fd95f9b..78a2577e 100644
--- a/includes/ingest.form.inc
+++ b/includes/ingest.form.inc
@@ -882,8 +882,6 @@ function islandora_ingest_form_load_include(array &$form_state) {
  *
  * Sorted by weight expected range between -50 to 50.
  *
- * The sort order is undefined for steps which have the same weight.
- *
  * @param array $form_state
  *   The Drupal form state.
  *
@@ -917,7 +915,7 @@ function islandora_ingest_form_get_steps(array &$form_state) {
   foreach ($steps as $key => &$step) {
     $step['id'] = $key;
   }
-  uasort($steps, 'drupal_sort_weight');
+  islandora_sort_ordered($steps, array('weight'));
   return $steps;
 }
 
diff --git a/includes/utilities.inc b/includes/utilities.inc
index dcbaab02..13f97d21 100644
--- a/includes/utilities.inc
+++ b/includes/utilities.inc
@@ -966,3 +966,41 @@ function islandora_build_datastream_edit_registry(AbstractDatastream $datastream
   drupal_alter(ISLANDORA_EDIT_DATASTREAM_REGISTRY_HOOK, $edit_registry, $context);
   return $edit_registry;
 }
+
+/**
+ * Sorts a structured array by a user selectable element.
+ *
+ * This function will preserve the order of elements in the array with the
+ * same weight.
+ *
+ * @param array $array
+ *   The array to be sorted.
+ * @param array $sort_keys
+ *   An array containing the keys to sort the array by.
+ */
+function islandora_sort_ordered(&$array, $sort_keys) {
+  $array_temp = array();
+  foreach ($array as $key => $value) {
+    $weight = $value;
+
+    foreach ($sort_keys as $sort_key) {
+      if (is_array($weight) && isset($weight[$sort_key])) {
+        $weight = $weight[$sort_key];
+      }
+      else {
+        $weight = 0;
+        break;
+      }
+    }
+
+    $array_temp[$weight][$key] = $value;
+    unset($array[$key]);
+  }
+
+  ksort($array_temp);
+
+  foreach ($array_temp as $key => $value) {
+    $array += $value;
+    unset($array_temp[$key]);
+  }
+}
diff --git a/islandora.info b/islandora.info
index 55c50359..1e84ce16 100644
--- a/islandora.info
+++ b/islandora.info
@@ -27,4 +27,5 @@ files[] = tests/datastream_versions.test
 files[] = tests/datastream_cache.test
 files[] = tests/derivatives.test
 files[] = tests/datastream_validator_tests.test
+files[] = tests/utilities.test
 php = 5.3
diff --git a/tests/utilities.test b/tests/utilities.test
new file mode 100644
index 00000000..4bbaf3be
--- /dev/null
+++ b/tests/utilities.test
@@ -0,0 +1,131 @@
+<?php
+
+/**
+ * @file
+ * Unit tests for the functions in the includes/utilities.inc file.
+ */
+
+/**
+ * Tests for drupal_sort_weight_ordered().
+ */
+class IslandoraSortOrderedTestCase extends DrupalUnitTestCase {
+
+  /**
+   * Return info about the tests.
+   */
+  public static function getInfo() {
+    return array(
+      'name' => 'islandora_sort_ordered()',
+      'description' => 'Performs unit tests on islandora_sort_oredered().',
+      'group' => 'Islandora',
+    );
+  }
+
+  /**
+   * Test sort order when sorting by weight.
+   */
+  public function testIslandoraSortOrderedSorting() {
+    module_load_include('inc', 'islandora', 'includes/utilities');
+
+    // The order of children with same weight should be preserved.
+    $element_mixed_weight = array(
+      'child5' => array('weight' => 10),
+      'child3' => array('weight' => -10),
+      'child1' => array(),
+      'child4' => array('weight' => 10),
+      'child2' => array(),
+      'child6' => array('weight' => 10),
+      'child9' => array(),
+      'child8' => array('weight' => 10),
+      'child7' => array(),
+    );
+
+    $expected = array(
+      'child3' => array('weight' => -10),
+      'child1' => array(),
+      'child2' => array(),
+      'child9' => array(),
+      'child7' => array(),
+      'child5' => array('weight' => 10),
+      'child4' => array('weight' => 10),
+      'child6' => array('weight' => 10),
+      'child8' => array('weight' => 10),
+    );
+
+    islandora_sort_ordered($element_mixed_weight, array('weight'));
+
+    $this->assertEqual($expected, $element_mixed_weight, 'Order of elements with the same weight is preserved.');
+  }
+
+  /**
+   * Make sure numeric keys are preserved.
+   */
+  public function testIslandoraSortPreserveNumeric() {
+    module_load_include('inc', 'islandora', 'includes/utilities');
+
+    // The order of children with same weight should be preserved.
+    $element_mixed_weight = array(
+      5 => array('weight' => 10),
+      3 => array('weight' => -10),
+      1 => array(),
+      4 => array('weight' => 10),
+      2 => array(),
+      6 => array('weight' => 10),
+      9 => array(),
+      8 => array('weight' => 10),
+      7 => array(),
+    );
+
+    $expected = array(
+      3 => array('weight' => -10),
+      1 => array(),
+      2 => array(),
+      9 => array(),
+      7 => array(),
+      5 => array('weight' => 10),
+      4 => array('weight' => 10),
+      6 => array('weight' => 10),
+      8 => array('weight' => 10),
+    );
+
+    islandora_sort_ordered($element_mixed_weight, array('weight'));
+
+    $this->assertEqual($expected, $element_mixed_weight, 'Numeric keys are preserved while sorting.');
+  }
+
+  /**
+   * Test sort order when sorting by a key in a multidimensional array.
+   */
+  public function testIslandoraSortOrderedMulti() {
+    module_load_include('inc', 'islandora', 'includes/utilities');
+
+    // The order of children with same weight should be preserved.
+    $element_mixed_weight = array(
+      'child5' => array('foo' => array('bar' => 10)),
+      'child3' => array('foo' => array('bar' => -10)),
+      'child1' => array('foo' => 6),
+      'child4' => array('foo' => array('bar' => 10)),
+      'child2' => array(),
+      'child6' => array('foo' => array('bar' => 10)),
+      'child9' => array(array('woot')),
+      'child8' => array('foo' => array('bar' => 10)),
+      'child7' => array(),
+    );
+
+    $expected = array(
+      'child3' => array('foo' => array('bar' => -10)),
+      'child1' => array('foo' => 6),
+      'child2' => array(),
+      'child9' => array(array('woot')),
+      'child7' => array(),
+      'child5' => array('foo' => array('bar' => 10)),
+      'child4' => array('foo' => array('bar' => 10)),
+      'child6' => array('foo' => array('bar' => 10)),
+      'child8' => array('foo' => array('bar' => 10)),
+    );
+
+    islandora_sort_ordered($element_mixed_weight, array('foo', 'bar'));
+
+    $this->assertEqual($expected, $element_mixed_weight, 'Sorting by multidimensional array works.');
+  }
+}