diff --git a/modules/field/field.install b/modules/field/field.install
index d56eb90..8e48155 100644
--- a/modules/field/field.install
+++ b/modules/field/field.install
@@ -435,5 +435,51 @@ 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(', ', $changed_fields),
+    )));
+  }
+}
+
+/**
  * @} End of "addtogroup updates-6.x-to-7.x"
  */
diff --git a/modules/node/node.install b/modules/node/node.install
index 2498091..46771f1 100644
--- a/modules/node/node.install
+++ b/modules/node/node.install
@@ -708,9 +708,12 @@ function node_update_7006(&$sandbox) {
             'type' => $revision->type,
           );
           // After node_update_7009() we will always have LANGUAGE_NONE as
-          // language neutral language code, but here we still have empty
-          // strings.
-          $langcode = empty($revision->language) ? LANGUAGE_NONE : $revision->language;
+          // language neutral language code, but here we still don't have
+          // those, so let's stick with LANGUAGE_NONE here: Drupal 6 has
+          // translation support only for content types, not for fields, so
+          // any and all fields upgraded from Drupal 6 should NOT be
+          // language-aware, including body.
+          $langcode = LANGUAGE_NONE;
           if (!empty($revision->teaser) && $revision->teaser != text_summary($revision->body)) {
             $node->body[$langcode][0]['summary'] = $revision->teaser;
           }