diff --git a/res/values/ids.xml b/res/values/ids.xml
index dbed28a..5746232 100644
--- a/res/values/ids.xml
+++ b/res/values/ids.xml
@@ -40,4 +40,9 @@
     <item type="id" name="dialog_reading_vcard" />
     <item type="id" name="dialog_io_exception" />
 
+    <!-- For ExportVCard -->
+    <item type="id" name="dialog_confirm_export_vcard" />
+    <item type="id" name="dialog_exporting_vcard" />
+    <item type="id" name="dialog_fail_to_export_with_reason" />
+
 </resources>
diff --git a/res/values/strings.xml b/res/values/strings.xml
index f358592..c033f8c 100644
--- a/res/values/strings.xml
+++ b/res/values/strings.xml
@@ -764,6 +764,10 @@
     <!-- The failed reason: "One or more files failed to be imported. (&lt;a list of file names&gt;)" -->
     <string name="fail_reason_failed_to_read_files">One or more files failed to be imported (%s).</string>
 
+    <!-- The failed reason: "Unknown error". This message should not be shown
+         but it may in some buggy condition. -->
+    <string name="fail_reason_unknown">Unknown error</string>
+
     <!-- Dialog title shown when a user is asked to select VCard file -->
     <string name="select_vcard_title">Select vCard file</string>