diff --git a/src/mm-sms.c b/src/mm-sms.c
index 41ca5f52..542230d7 100644
--- a/src/mm-sms.c
+++ b/src/mm-sms.c
@@ -138,6 +138,24 @@ mm_sms_multipart_is_complete (MMSms *self)
 
 /*****************************************************************************/
 
+static guint
+cmp_sms_part_index (MMSmsPart *part,
+                    gpointer user_data)
+{
+    return (GPOINTER_TO_UINT (user_data) - mm_sms_part_get_index (part));
+}
+
+gboolean
+mm_sms_has_part_index (MMSms *self,
+                       guint index)
+{
+    return !!g_list_find_custom (self->priv->parts,
+                                 GUINT_TO_POINTER (index),
+                                 (GCompareFunc)cmp_sms_part_index);
+}
+
+/*****************************************************************************/
+
 static guint
 cmp_sms_part_sequence (MMSmsPart *a,
                        MMSmsPart *b)
diff --git a/src/mm-sms.h b/src/mm-sms.h
index 04bc7bb8..9f84eb0c 100644
--- a/src/mm-sms.h
+++ b/src/mm-sms.h
@@ -66,6 +66,10 @@ gboolean  mm_sms_multipart_take_part (MMSms *self,
 
 void         mm_sms_export       (MMSms *self);
 const gchar *mm_sms_get_path     (MMSms *self);
+
+gboolean     mm_sms_has_part_index (MMSms *self,
+                                    guint index);
+
 gboolean     mm_sms_is_multipart            (MMSms *self);
 guint        mm_sms_get_multipart_reference (MMSms *self);
 gboolean     mm_sms_multipart_is_complete   (MMSms *self);