diff --git a/src/frontends/qt4/GuiApplication.cpp b/src/frontends/qt4/GuiApplication.cpp
index 1b1daf82d5..030668f2e9 100644
--- a/src/frontends/qt4/GuiApplication.cpp
+++ b/src/frontends/qt4/GuiApplication.cpp
@@ -1020,6 +1020,7 @@ void GuiApplication::dispatch(FuncRequest const & cmd, DispatchResult & dr)
 		Buffer * buf = current_view_->loadDocument(fname, false);
 		if (buf) {
 			current_view_->setBuffer(buf);
+			buf->setReadonly(true);
 			buf->updateLabels();
 			buf->errors("Parse");
 		}