diff --git a/redirect.module b/redirect.module
index 8c47b75..051f464 100644
--- a/redirect.module
+++ b/redirect.module
@@ -393,6 +393,13 @@ function redirect_path_update(array $path) {
     return;
   }
 
+  if (!empty($path['alias'])) {
+    // !An alias can't be used as a source, it has to be the original.  Since an alias is
+    // preferable to a redirect and there's no hook_path_validate() to stop them anyway,
+    // we defer to the alias.
+    redirect_free_source($path['alias']);
+  }
+
   if (!empty($path['original']['pid']) && $path['original']['pid'] == $path['pid'] && $path['original']['alias'] != $path['alias']) {
     $redirect = new stdClass();
     redirect_object_prepare($redirect);
@@ -408,6 +415,41 @@ function redirect_path_update(array $path) {
 }
 
 /**
+ * Implements hook_path_insert().
+ */
+function redirect_path_insert(array $path) {
+  if (!empty($path['alias'])) {
+    //! No hook_path_validate(), and alias beats redirect
+    redirect_free_source($path['alias']);
+  }
+}
+
+/**
+ * Ensures that a source path is available.  Warns the user if it deletes an existing record.
+ *
+ * Similar to redirect_delete_by_path(), but doesn't recurse sub-paths.  This is called on
+ * redirect_path_*() to make sure we don't duplicate the work of an alias (which would cause
+ * an internal loop).
+ *
+ * @param $source
+ *   The redirect source path.
+ *
+ * @return
+ *   The deleted redirect object, or FALSE if nothing found.
+ *
+ * @ingroup redirect_api
+ */
+function redirect_free_source($source) {
+  $redirect_record = redirect_load_by_source($source);
+  if ($redirect_record) {
+    redirect_delete($redirect_record->rid);
+    $warning = t('A @type record using the path @source (pointing to @redirect) has been removed.', array('@type' => $redirect_record->type, '@source' => $redirect_record->source, '@redirect' => $redirect_record->redirect));
+    drupal_set_message($warning,'warning');
+  }
+  return $redirect_record;
+}
+
+/**
  * Implements hook_path_delete().
  */
 function redirect_path_delete($path) {