diff --git l10n_client.module l10n_client.module
index 9cd47ad..9fb9488 100644
--- l10n_client.module
+++ l10n_client.module
@@ -498,13 +498,15 @@ function l10n_client_import_package_form_submit($form, &$form_state) {
     $query->condition('textgroup', $textgroups);
     $lids = $query->execute()->fetchCol('lid');
 
-    db_delete('locales_target')
-      ->condition('language', $langcodes)
-      ->condition('lid', $lids)
-      ->execute();
-
-    // Also remove all source strings without translations.
-    db_query("DELETE FROM {locales_source} WHERE lid NOT IN (SELECT lid FROM {locales_target})");
+    if (!empty($textgroups)) {
+      db_delete('locales_target')
+        ->condition('language', $langcodes)
+        ->condition('lid', $lids)
+        ->execute();
+
+      // Also remove all source strings without translations.
+      db_query("DELETE FROM {locales_source} WHERE lid NOT IN (SELECT lid FROM {locales_target})");
+    }
   }
 
   // Set up and start batch for new imports.