diff --git a/src/matrix-api.c b/src/matrix-api.c
index 990b9f2..cf8fbb3 100644
--- a/src/matrix-api.c
+++ b/src/matrix-api.c
@@ -753,6 +753,9 @@ void matrix_api_toggle_pusher(MatrixAPI *api,
  *                 list of state events to set in the new room
  * @invitees: (element-type utf8) (allow-none): list of user IDs to
  *            invite to the new room
+ * @invite_3pids: (element-type MatrixAPI3PidCredential) (allow-none):
+ *                 a list of 3rd party credentials to invite to the
+ *                 new room
  * @error: return location for a #GError, or %NULL
  *
  * Create a new room with the given name and invite the users in
@@ -770,6 +773,7 @@ matrix_api_create_room(MatrixAPI *api,
                        JsonNode *creation_content,
                        GList *initial_state,
                        GList *invitees,
+                       GList *invite_3pids,
                        GError **error)
 {
     g_return_if_fail(MATRIX_IS_API(api));
@@ -778,7 +782,7 @@ matrix_api_create_room(MatrixAPI *api,
         ->create_room(api, callback, user_data,
                       preset, room_name, room_alias, topic,
                       visibility, creation_content,
-                      initial_state, invitees,
+                      initial_state, invitees, invite_3pids,
                       error);
 }
 
diff --git a/src/matrix-api.h b/src/matrix-api.h
index cf47b05..0e865c0 100644
--- a/src/matrix-api.h
+++ b/src/matrix-api.h
@@ -167,6 +167,7 @@ struct _MatrixAPIInterface {
                         JsonNode *creation_content,
                         GList *initial_state,
                         GList *invitees,
+                        GList *invite_3pids,
                         GError **error);
 
     /* Room directory */
@@ -589,6 +590,7 @@ void matrix_api_create_room(MatrixAPI *api,
                             JsonNode *creation_content,
                             GList *initial_state,
                             GList *invitees,
+                            GList *invite_3pids,
                             GError **error);
 
 /* Room directory */
diff --git a/src/matrix-http-api.c b/src/matrix-http-api.c
index 1d4715e..acf09a9 100644
--- a/src/matrix-http-api.c
+++ b/src/matrix-http-api.c
@@ -870,6 +870,28 @@ add_string(gchar *str, JsonBuilder *builder)
     json_builder_add_string_value(builder, str);
 }
 
+typedef struct {
+    JsonBuilder *builder;
+    GError *error;
+} Add3PidCredData;
+
+static void
+add_3pidcred(MatrixAPI3PidCredential *credential, Add3PidCredData *data)
+{
+    JsonNode *node;
+
+    // If there is already an error set, return immediately
+    if (data->error) {
+        return;
+    }
+
+    // Get the credentials’ JSON representation
+    node = matrix_api_3pid_credential_get_json_node(credential, &(data->error));
+
+    // Add it to the builder
+    json_builder_add_value(data->builder, node);
+}
+
 static void
 i_create_room(MatrixAPI *api,
               MatrixAPICallback callback,
@@ -882,6 +904,7 @@ i_create_room(MatrixAPI *api,
               JsonNode *creation_content,
               GList *initial_state,
               GList *invitees,
+              GList *invite_3pids,
               GError **error)
 {
     JsonNode *body;
@@ -910,6 +933,27 @@ i_create_room(MatrixAPI *api,
         json_builder_end_array(builder);
     }
 
+    if (invite_3pids) {
+        Add3PidCredData add_data;
+
+        add_data.builder = builder;
+        add_data.error = NULL;
+
+        json_builder_set_member_name(builder, "invite_3pid");
+        json_builder_begin_array(builder);
+        g_list_foreach(invite_3pids, (GFunc)add_3pidcred, &add_data);
+
+        if (add_data.error) {
+            g_propagate_error(error, add_data.error);
+
+            g_object_unref(builder);
+
+            return;
+        }
+
+        json_builder_end_array(builder);
+    }
+
     if (room_name) {
         json_builder_set_member_name(builder, "name");
         json_builder_add_string_value(builder, room_name);
diff --git a/src/test-client.c b/src/test-client.c
index 74e800a..62268cf 100644
--- a/src/test-client.c
+++ b/src/test-client.c
@@ -141,7 +141,7 @@ login_finished(MatrixAPI *api,
                                "GLib SDK test room", "matrix-glib-sdk-test",
                                "GLib SDK test room",
                                MATRIX_API_ROOM_VISIBILITY_DEFAULT,
-                               NULL, NULL, NULL, NULL);
+                               NULL, NULL, NULL, NULL, NULL);
         matrix_api_get_presence_list(api, NULL, NULL, user_id, NULL);
         matrix_api_get_user_presence(api,
                                      get_user_presence_finished, NULL,