Index: gio/gio.override
===================================================================
--- gio/gio.override	(revision 979)
+++ gio/gio.override	(working copy)
@@ -36,6 +36,8 @@
 typedef struct {
     PyObject *callback;
     PyObject *data;
+    gpointer  buffer;
+    gsize     buffer_size;
 } PyGIONotify;
 
 static void
@@ -45,10 +47,22 @@
 }
 
 static void
+pygio_notify_copy_buffer(PyGIONotify *notify, gpointer buffer, gsize buffer_size)
+{
+    if (buffer_size > 0) {
+	notify->buffer = g_slice_copy(buffer_size, buffer);
+	notify->buffer_size = buffer_size;
+    }
+}
+
+static void
 pygio_free_notify(PyGIONotify *notify)
 {
     Py_XDECREF(notify->callback);
     Py_XDECREF(notify->data);
+    if (notify->buffer)
+	g_slice_free1(notify->buffer_size, notify->buffer);
+
     g_slice_free(PyGIONotify, notify);
 }
 
Index: gio/goutputstream.override
===================================================================
--- gio/goutputstream.override	(revision 979)
+++ gio/goutputstream.override	(working copy)
@@ -130,9 +130,10 @@
   if (!pygio_check_cancellable(pycancellable, &cancellable))
       return NULL;
 
+  pygio_notify_copy_buffer(notify, buffer, count);
   g_output_stream_write_async(G_OUTPUT_STREAM(self->obj),
-			      buffer,
-			      count,
+			      notify->buffer,
+			      notify->buffer_size,
 			      io_priority,
 			      cancellable,
 			      (GAsyncReadyCallback)async_result_callback_marshal,
Index: gio/gfile.override
===================================================================
--- gio/gfile.override	(revision 979)
+++ gio/gfile.override	(working copy)
@@ -1110,9 +1110,10 @@
 
     Py_INCREF(notify->callback);
     Py_XINCREF(notify->data);
+    pygio_notify_copy_buffer(notify, contents, length);
     g_file_replace_contents_async(G_FILE(self->obj),
-                                  contents,
-                                  length,
+                                  notify->buffer,
+                                  notify->buffer_size,
                                   etag,
                                   make_backup,
                                   flags,
