diff --git a/desktop/source/lib/init.cxx b/desktop/source/lib/init.cxx
index bc38cc2720be..53e49e3b0d56 100644
--- a/desktop/source/lib/init.cxx
+++ b/desktop/source/lib/init.cxx
@@ -276,6 +276,8 @@ static LibreOfficeKitDocument* lo_documentLoad(LibreOfficeKit* pThis, const char
 
     OUString aURL = getAbsoluteURL(pURL);
 
+    SolarMutexGuard aGuard;
+
     uno::Reference<frame::XDesktop2> xComponentLoader = frame::Desktop::create(xContext);
 
     pLib->maLastExceptionMsg = "";