diff --git a/simpletest.install b/simpletest.install
index 0f017e7..c56cacb 100644
--- a/simpletest.install
+++ b/simpletest.install
@@ -167,6 +167,9 @@ function simpletest_schema() {
  * Implements hook_uninstall().
  */
 function simpletest_uninstall() {
+  // At this point the module is disabled so the simpletest.module file has to
+  // be manually loaded.
+  module_load_include('module', 'simpletest');
   simpletest_clean_environment();
 
   // Remove settings variables.