diff --git a/vcl/source/components/dtranscomp.cxx b/vcl/source/components/dtranscomp.cxx
index bb771b2dca81..9621154d0537 100644
--- a/vcl/source/components/dtranscomp.cxx
+++ b/vcl/source/components/dtranscomp.cxx
@@ -133,6 +133,7 @@ sal_Bool GenericClipboard::supportsService( const OUString& ServiceName )
 
 Reference< css::datatransfer::XTransferable > GenericClipboard::getContents()
 {
+    std::unique_lock aGuard(m_aMutex);
     return m_aContents;
 }