diff --git a/lib/navigationlib.php b/lib/navigationlib.php
index 092049a990f..c0159b986ac 100644
--- a/lib/navigationlib.php
+++ b/lib/navigationlib.php
@@ -901,6 +901,7 @@ class navigation_node_collection implements IteratorAggregate {
             foreach ($this->collection as $colkey => $node) {
                 if ($node->key === $key && $node->type == $type) {
                     unset($this->collection[$colkey]);
+                    $this->collection = array_values($this->collection);
                     break;
                 }
             }
diff --git a/lib/tests/navigationlib_test.php b/lib/tests/navigationlib_test.php
index e430677f753..5f60229caa7 100644
--- a/lib/tests/navigationlib_test.php
+++ b/lib/tests/navigationlib_test.php
@@ -258,9 +258,19 @@ class navigation_node_testcase extends basic_testcase {
         $this->assertFalse($this->node->get('remove1'));
         $this->assertFalse(in_array('remove1', $this->node->get_children_key_list(), true));
 
+        // Make sure that we can insert element after removal
+        $insertelement = navigation_node::create('extra element 4', null, navigation_node::TYPE_CUSTOM, null, 'element4');
+        $this->node->add_node($insertelement, 'remove2');
+        $this->assertNotEmpty($this->node->get('element4'));
+
         // Remove more elements
         $this->assertTrue($this->node->get('remove2')->remove());
         $this->assertFalse($this->node->get('remove2'));
+
+        // Make sure that we can add element after removal
+        $this->node->add('extra element 5', null, navigation_node::TYPE_CUSTOM, null, 'element5');
+        $this->assertNotEmpty($this->node->get('element5'));
+
         $this->assertTrue($remove2->get('remove3')->remove());
 
         $this->assertFalse($this->node->get('remove1'));