diff --git a/chart2/source/model/main/ChartModel.cxx b/chart2/source/model/main/ChartModel.cxx
index 950169395c95..5a30d97118c5 100755
--- a/chart2/source/model/main/ChartModel.cxx
+++ b/chart2/source/model/main/ChartModel.cxx
@@ -1043,6 +1043,7 @@ void SAL_CALL ChartModel::setVisualAreaSize( ::sal_Int64 nAspect, const awt::Siz
 {
     if( nAspect == embed::Aspects::MSOLE_CONTENT )
     {
+        ControllerLockGuard aLockGuard( this );
         bool bChanged =
             (m_aVisualAreaSize.Width != aSize.Width ||
              m_aVisualAreaSize.Height != aSize.Height);