diff --git a/src/calls-dummy-call.c b/src/calls-dummy-call.c
index daf6312..473ccfa 100644
--- a/src/calls-dummy-call.c
+++ b/src/calls-dummy-call.c
@@ -23,6 +23,7 @@
  */
 
 #include "calls-dummy-call.h"
+#include "calls-message-source.h"
 #include "calls-call.h"
 
 #include <glib/gi18n.h>
@@ -35,9 +36,12 @@ struct _CallsDummyCall
   CallsCallState state;
 };
 
+static void calls_dummy_call_message_source_interface_init (CallsCallInterface *iface);
 static void calls_dummy_call_call_interface_init (CallsCallInterface *iface);
 
 G_DEFINE_TYPE_WITH_CODE (CallsDummyCall, calls_dummy_call, G_TYPE_OBJECT,
+                         G_IMPLEMENT_INTERFACE (CALLS_TYPE_MESSAGE_SOURCE,
+                                                calls_dummy_call_message_source_interface_init)
                          G_IMPLEMENT_INTERFACE (CALLS_TYPE_CALL,
                                                 calls_dummy_call_call_interface_init))
 
@@ -192,6 +196,13 @@ calls_dummy_call_call_interface_init (CallsCallInterface *iface)
   iface->tone_stop = tone_stop;
 }
 
+
+static void
+calls_dummy_call_message_source_interface_init (CallsCallInterface *iface)
+{
+}
+
+
 static void
 calls_dummy_call_init (CallsDummyCall *self)
 {
diff --git a/src/calls-dummy-origin.c b/src/calls-dummy-origin.c
index b889a9a..678a646 100644
--- a/src/calls-dummy-origin.c
+++ b/src/calls-dummy-origin.c
@@ -23,6 +23,7 @@
  */
 
 #include "calls-dummy-origin.h"
+#include "calls-message-source.h"
 #include "calls-origin.h"
 #include "calls-dummy-call.h"
 
@@ -37,9 +38,12 @@ struct _CallsDummyOrigin
   GList *calls;
 };
 
+static void calls_dummy_origin_message_source_interface_init (CallsOriginInterface *iface);
 static void calls_dummy_origin_origin_interface_init (CallsOriginInterface *iface);
 
 G_DEFINE_TYPE_WITH_CODE (CallsDummyOrigin, calls_dummy_origin, G_TYPE_OBJECT,
+                         G_IMPLEMENT_INTERFACE (CALLS_TYPE_MESSAGE_SOURCE,
+                                                calls_dummy_origin_message_source_interface_init)
                          G_IMPLEMENT_INTERFACE (CALLS_TYPE_ORIGIN,
                                                 calls_dummy_origin_origin_interface_init))
 
@@ -150,36 +154,9 @@ dial (CallsOrigin *origin, const gchar *number)
 CallsDummyOrigin *
 calls_dummy_origin_new (const gchar *name)
 {
-  /*
-  guint n_properties, i;
-  const gchar *names[1] = { NULL };
-  GValue values[1] = { G_VALUE_INIT };
-  GObject *object;
-
-  if (name == NULL)
-    {
-      n_properties = 0;
-    }
-  else
-    {
-      n_properties = 1;
-      names[0] = "name";
-      g_value_init (&values[0], G_TYPE_STRING);
-      g_value_set_string (&values[0], name);
-    }
-
-  object = g_object_new_with_properties (CALLS_TYPE_DUMMY_ORIGIN,
-                                         n_properties, names, values);
-
-  for (i = 0; i < n_properties; ++i)
-    {
-      g_value_unset (&values[i]);
-    }
-
-  return CALLS_DUMMY_ORIGIN(object);
-  */
-  // FIXME
-  return NULL;
+  return g_object_new (CALLS_TYPE_DUMMY_ORIGIN,
+                       "name", name,
+                       NULL);
 }
 
 
@@ -247,6 +224,12 @@ calls_dummy_origin_class_init (CallsDummyOriginClass *klass)
 }
 
 
+static void
+calls_dummy_origin_message_source_interface_init (CallsOriginInterface *iface)
+{
+}
+
+
 static void
 calls_dummy_origin_origin_interface_init (CallsOriginInterface *iface)
 {
diff --git a/src/calls-dummy-provider.c b/src/calls-dummy-provider.c
index bdd10c1..55b2d32 100644
--- a/src/calls-dummy-provider.c
+++ b/src/calls-dummy-provider.c
@@ -23,6 +23,7 @@
  */
 
 #include "calls-dummy-provider.h"
+#include "calls-message-source.h"
 #include "calls-provider.h"
 #include "calls-dummy-origin.h"
 
@@ -33,18 +34,23 @@ struct _CallsDummyProvider
   GList *origins;
 };
 
+static void calls_dummy_provider_message_source_interface_init (CallsProviderInterface *iface);
 static void calls_dummy_provider_provider_interface_init (CallsProviderInterface *iface);
 
 G_DEFINE_TYPE_WITH_CODE (CallsDummyProvider, calls_dummy_provider, G_TYPE_OBJECT,
+                         G_IMPLEMENT_INTERFACE (CALLS_TYPE_MESSAGE_SOURCE,
+                                                calls_dummy_provider_message_source_interface_init)
                          G_IMPLEMENT_INTERFACE (CALLS_TYPE_PROVIDER,
                                                 calls_dummy_provider_provider_interface_init))
 
+
 static const gchar *
 get_name (CallsProvider *iface)
 {
   return "Dummy provider";
 }
 
+
 static GList *
 get_origins (CallsProvider *iface)
 {
@@ -52,6 +58,7 @@ get_origins (CallsProvider *iface)
   return g_list_copy (self->origins);
 }
 
+
 CallsDummyProvider *
 calls_dummy_provider_new ()
 {
@@ -71,6 +78,7 @@ dispose (GObject *object)
   parent_class->dispose (object);
 }
 
+
 static void
 calls_dummy_provider_class_init (CallsDummyProviderClass *klass)
 {
@@ -79,6 +87,13 @@ calls_dummy_provider_class_init (CallsDummyProviderClass *klass)
   object_class->dispose = dispose;
 }
 
+
+static void
+calls_dummy_provider_message_source_interface_init (CallsProviderInterface *iface)
+{
+}
+
+
 static void
 calls_dummy_provider_provider_interface_init (CallsProviderInterface *iface)
 {
@@ -86,11 +101,17 @@ calls_dummy_provider_provider_interface_init (CallsProviderInterface *iface)
   iface->get_origins = get_origins;
 }
 
+
 static void
 calls_dummy_provider_init (CallsDummyProvider *self)
 {
-  self->origins = g_list_append (self->origins,
-                                 calls_dummy_origin_new (NULL));
-  self->origins = g_list_append (self->origins,
-                                 calls_dummy_origin_new ("Dummy origin 2"));
+}
+
+
+void
+calls_dummy_provider_add_origin (CallsDummyProvider *self,
+                                 const gchar        *name)
+{
+  self->origins = g_list_append (self->origins,
+                                 calls_dummy_origin_new (name));
 }
diff --git a/src/calls-dummy-provider.h b/src/calls-dummy-provider.h
index f7b3071..2862e3f 100644
--- a/src/calls-dummy-provider.h
+++ b/src/calls-dummy-provider.h
@@ -33,7 +33,9 @@ G_BEGIN_DECLS
 
 G_DECLARE_FINAL_TYPE (CallsDummyProvider, calls_dummy_provider, CALLS, DUMMY_PROVIDER, GObject);
 
-CallsDummyProvider *calls_dummy_provider_new ();
+CallsDummyProvider *calls_dummy_provider_new        ();
+void                calls_dummy_provider_add_origin (CallsDummyProvider *self,
+                                                     const gchar        *name);
 
 G_END_DECLS