diff --git a/chart2/source/tools/ReferenceSizeProvider.cxx b/chart2/source/tools/ReferenceSizeProvider.cxx
index 6135724dca5d..d7ae7f76a2fd 100644
--- a/chart2/source/tools/ReferenceSizeProvider.cxx
+++ b/chart2/source/tools/ReferenceSizeProvider.cxx
@@ -92,6 +92,8 @@ void ReferenceSizeProvider::setValuesAtTitle(
 
 void ReferenceSizeProvider::setValuesAtAllDataSeries()
 {
+    if (!m_xChartDoc)
+        return;
     rtl::Reference< Diagram > xDiagram( m_xChartDoc->getFirstChartDiagram());
     if (!xDiagram)
         return;