diff --git a/core/modules/simpletest/simpletest.install b/core/modules/simpletest/simpletest.install
index c1422e6..9d2cae5 100644
--- a/core/modules/simpletest/simpletest.install
+++ b/core/modules/simpletest/simpletest.install
@@ -94,10 +94,8 @@ function simpletest_schema() {
         'description' => 'Test ID, messages belonging to the same ID are reported together',
       ),
       'test_class' => array(
-        'type' => 'varchar_ascii',
-        'length' => 255,
+        'type' => 'text',
         'not null' => TRUE,
-        'default' => '',
         'description' => 'The name of the class that created this message.',
       ),
       'status' => array(
@@ -120,10 +118,8 @@ function simpletest_schema() {
         'description' => 'The message group this message belongs to. For example: warning, browser, user.',
       ),
       'function' => array(
-        'type' => 'varchar_ascii',
-        'length' => 255,
+        'type' => 'text',
         'not null' => TRUE,
-        'default' => '',
         'description' => 'Name of the assertion function or method that created this message.',
       ),
       'line' => array(
@@ -142,7 +138,7 @@ function simpletest_schema() {
     ),
     'primary key' => array('message_id'),
     'indexes' => array(
-      'reporter' => array('test_class', 'message_id'),
+      'reporter' => array(array('test_class', 255), 'message_id'),
     ),
   );
   $schema['simpletest_test_id'] = array(
@@ -180,3 +176,21 @@ function simpletest_uninstall() {
   // Delete verbose test output and any other testing framework files.
   file_unmanaged_delete_recursive('public://simpletest');
 }
+
+/**
+ * Implements hook_update()
+ * Changing type to 'text'.
+ * Removing the default value.
+ */
+function simpletest_update_8102() {
+  db_change_field('simpletest', 'test_class', 'test_class', array(
+    'type' => 'text',
+    'not null' => TRUE,
+    'description' => 'The name of the class that created this message.',
+  ));
+  db_change_field('simpletest', 'function', 'function', array(
+    'type' => 'text',
+    'not null' => TRUE,
+    'description' => 'Name of the assertion function or method that created this message.',
+  ));
+}