diff --git a/modules/field/field.install b/modules/field/field.install
index d56eb90..070325d 100644
--- a/modules/field/field.install
+++ b/modules/field/field.install
@@ -435,5 +435,91 @@ function field_update_7001() {
 }
 
 /**
+ * Disable 'translatable' flag for all fields that do not contain language-specific field values.
+ */
+function field_update_7002() {
+  $fields = _update_7000_field_read_fields(array(
+    // Only currently enabled fields are affected.
+    'translatable' => 1,
+    // Field storage engines depend on the module and hook system; we can only
+    // query and update fields in SQL. Alternative field storage engines have to
+    // implement a corresponding module update on their own.
+    'storage_type' => 'field_sql_storage',
+    // Field configuration and values of deleted fields are irrelevant.
+    'deleted' => 0,
+  ));
+  $changed_fields = array();
+  foreach ($fields as $field) {
+    $tables = array("field_data_{$field['field_name']}", "field_revision_{$field['field_name']}");
+    $has_language = FALSE;
+    foreach ($tables as $table) {
+      // 'und' denotes LANGUAGE_NONE; constant values may change over time.
+      $query = db_select($table)->condition('language', 'und', '<>')->range(0, 1);
+      $query->addExpression(1);
+      $has_language = $has_language || $query->execute()->fetchField();
+    }
+    // Only in case there is no language-specific field value, update the
+    // field's configuration to mark it untranslatable.
+    // Note: There is a small chance of disabling the translatable flag for
+    // fields that actually have a field translation handler associated (but
+    // e.g., no values yet). However, since the field translation handler
+    // entirely depends on module hooks, it is impossible to gather this
+    // information in a module update.
+    if (!$has_language) {
+      $changed_fields[] = $field['field_name'];
+      db_update('field_config')
+        ->condition('id', $field['id'])
+        ->fields(array('translatable' => 0))
+        ->execute();
+    }
+  }
+  if ($changed_fields) {
+    drupal_set_message(t('The following fields have been changed to be no longer translatable: %field-list.', array(
+      '%field-list' => implode(', ', $changed_fields),
+    )));
+  }
+}
+
+/**
  * @} End of "addtogroup updates-6.x-to-7.x"
  */
+
+/**
+ * Searches for localized field values of non-translatable fields and corrects them.
+ */
+function field_update_7003() {
+  $fields = _update_7000_field_read_fields(array(
+    // Only currently enabled fields are affected.
+    'translatable' => 0,
+    // Field storage engines depend on the module and hook system; we can only
+    // query and update fields in SQL. Alternative field storage engines have to
+    // implement a corresponding module update on their own.
+    'storage_type' => 'field_sql_storage',
+    // Field configuration and values of deleted fields are irrelevant.
+    'deleted' => 0,
+  ));
+  $changed_fields = array();
+  foreach ($fields as $field) {
+    $tables = array("field_data_{$field['field_name']}", "field_revision_{$field['field_name']}");
+    $has_language = FALSE;
+    foreach ($tables as $table) {
+      // 'und' denotes LANGUAGE_NONE; constant values may change over time.
+      $query = db_select($table)->condition('language', 'und', '<>')->range(0, 1);
+      $query->addExpression(1);
+      // Only in case there is language-specific field value, update the field
+      // value entries.
+      if ($query->execute()->fetchField()) {
+        $changed_fields[] = $field['field_name'];
+        db_update($table)
+          ->condition('language', 'und', '<>')
+          ->fields(array('language' => LANGUAGE_NONE))
+          ->execute();
+      }
+    }
+  }
+  if ($changed_fields) {
+    drupal_set_message(t('The following fields have been changed to be no longer translatable: %field-list.', array(
+      '%field-list' => implode(', ', $changed_fields),
+    )));
+  }
+}
diff --git a/modules/simpletest/simpletest.info b/modules/simpletest/simpletest.info
index f51804c..6b5f34d 100644
--- a/modules/simpletest/simpletest.info
+++ b/modules/simpletest/simpletest.info
@@ -45,5 +45,6 @@ files[] = tests/upgrade/upgrade.locale.test
 files[] = tests/upgrade/upgrade.menu.test
 files[] = tests/upgrade/upgrade.node.test
 files[] = tests/upgrade/upgrade.taxonomy.test
+files[] = tests/upgrade/upgrade.translatable.test
 files[] = tests/upgrade/upgrade.upload.test
 files[] = tests/upgrade/upgrade.user.test
diff --git a/modules/simpletest/tests/upgrade/drupal-6.translatable.database.php b/modules/simpletest/tests/upgrade/drupal-6.translatable.database.php
new file mode 100644
index 0000000..5162116
--- /dev/null
+++ b/modules/simpletest/tests/upgrade/drupal-6.translatable.database.php
@@ -0,0 +1,125 @@
+<?php
+
+/**
+ * Database additions for translatable tests.
+ */
+
+db_insert('node')->fields(array(
+  'nid',
+  'vid',
+  'type',
+  'language',
+  'title',
+  'uid',
+  'status',
+  'created',
+  'changed',
+  'comment',
+  'promote',
+  'moderate',
+  'sticky',
+  'tnid',
+  'translate',
+))
+->values(array(
+  'nid' => '53',
+  'vid' => '63',
+  'type' => 'translatable_page',
+  'language' => 'fr',
+  'title' => 'First translatable page',
+  'uid' => '1',
+  'status' => '1',
+  'created' => '1298363952',
+  'changed' => '1298363952',
+  'comment' => '2',
+  'promote' => '0',
+  'moderate' => '0',
+  'sticky' => '0',
+  'tnid' => '0',
+  'translate' => '0',
+))
+->execute();
+
+db_insert('node_revisions')->fields(array(
+  'nid',
+  'vid',
+  'uid',
+  'title',
+  'body',
+  'teaser',
+  'log',
+  'timestamp',
+  'format',
+))
+->values(array(
+  'nid' => '53',
+  'vid' => '63',
+  'uid' => '1',
+  'title' => 'First translatable page',
+  'body' => 'Body of the first translatable page.',
+  'teaser' => 'Teaser of the first translatable page.',
+  'log' => '',
+  'timestamp' => '1298363952',
+  'format' => '1',
+))
+->execute();
+
+db_insert('node_comment_statistics')->fields(array(
+  'nid',
+  'last_comment_timestamp',
+  'last_comment_name',
+  'last_comment_uid',
+  'comment_count',
+))
+->values(array(
+  'nid' => '53',
+  'last_comment_timestamp' => '1298363952',
+  'last_comment_name' => NULL,
+  'last_comment_uid' => '1',
+  'comment_count' => '0',
+))
+->execute();
+
+db_insert('node_type')->fields(array(
+  'type',
+  'name',
+  'module',
+  'description',
+  'help',
+  'has_title',
+  'title_label',
+  'has_body',
+  'body_label',
+  'min_word_count',
+  'custom',
+  'modified',
+  'locked',
+  'orig_type',
+))
+->values(array(
+  'type' => 'translatable_page',
+  'name' => 'Translatable page',
+  'module' => 'node',
+  'description' => 'A <em>translatable page</em> is like a normal page, but with multilanguage support.',
+  'help' => '',
+  'has_title' => '1',
+  'title_label' => 'Title',
+  'has_body' => '1',
+  'body_label' => 'Body',
+  'min_word_count' => '0',
+  'custom' => '0',
+  'modified' => '0',
+  'locked' => '1',
+  'orig_type' => '',
+))
+->execute();
+
+db_insert('variable')->fields(array(
+  'name',
+  'value',
+))
+->values(array(
+  'name' => 'language_content_type_translatable_page',
+  'value' => 's:1:"1";',
+))
+->execute();
diff --git a/modules/simpletest/tests/upgrade/upgrade.translatable.test b/modules/simpletest/tests/upgrade/upgrade.translatable.test
new file mode 100644
index 0000000..cb66e78
--- /dev/null
+++ b/modules/simpletest/tests/upgrade/upgrade.translatable.test
@@ -0,0 +1,51 @@
+<?php
+
+/**
+ * Upgrade test for translatable content types of node.module.
+ */
+class TranslatableUpgradePathTestCase extends UpgradePathTestCase {
+  public static function getInfo() {
+    return array(
+      'name'  => 'Translatable upgrade path',
+      'description'  => 'Upgrade path tests for the translatable content types of node.module.',
+      'group' => 'Upgrade path',
+    );
+  }
+
+  public function setUp() {
+    // Path to the database dump files.
+    $this->databaseDumpFiles = array(
+      drupal_get_path('module', 'simpletest') . '/tests/upgrade/drupal-6.filled.database.php',
+      drupal_get_path('module', 'simpletest') . '/tests/upgrade/drupal-6.locale.database.php',
+      drupal_get_path('module', 'simpletest') . '/tests/upgrade/drupal-6.translatable.database.php',
+    );
+    parent::setUp();
+
+    $this->uninstallModulesExcept(array('locale'));
+  }
+
+  /**
+   * Test a successful upgrade (no negotiation).
+   */
+  public function testTranslatableUpgrade() {
+    $this->assertTrue($this->performUpgrade(), t('The upgrade was completed successfully.'));
+
+    // The D6 database contains the translatable (English) node
+    // "First translatable page" with nid 53.
+    $nid = 53;
+    $title = 'First translatable page';
+    $teaser = 'Teaser of the first translatable page.';
+
+    // Check whether the node displays properly.
+    $this->drupalGet("node/$nid");
+    $this->assertText($body = 'Body of the first translatable page.', t('Translatable node body displays properly'));
+
+    // Retrieve node object, ensure that both the body and the teaser has
+    // survived upgrade properly.
+    $node = $this->drupalGetNodeByTitle($title);
+    $this->assertTrue($node != NULL, t('Node @title was loaded', array('@title' => $title)));
+    $this->verbose('Upgraded node: ' . var_export($node, TRUE));
+    $this->assertEqual($node->body[LANGUAGE_NONE][0]['value'], $body, 'Body of the node survided upgrade properly');
+    $this->assertEqual($node->body[LANGUAGE_NONE][0]['summary'], $teaser, 'Teaser of the node survided upgrade properly');
+  }
+}