diff --git a/ApplicationCode/UserInterface/RiuSummaryVectorSelectionUi.cpp b/ApplicationCode/UserInterface/RiuSummaryVectorSelectionUi.cpp
index 482ccc787f..61ec281d2b 100644
--- a/ApplicationCode/UserInterface/RiuSummaryVectorSelectionUi.cpp
+++ b/ApplicationCode/UserInterface/RiuSummaryVectorSelectionUi.cpp
@@ -649,16 +649,24 @@ void RiuSummaryVectorSelectionUi::setSelectedCurveDefinitions( const std::vector
         {
             if ( curveDef.ensemble() && !m_hideEnsembles )
             {
-                m_selectedSources.push_back( curveDef.ensemble() );
-                handleAddedSource( curveDef.ensemble() );
+                if ( std::find( m_selectedSources.begin(), m_selectedSources.end(), curveDef.ensemble() ) ==
+                     m_selectedSources.end() )
+                {
+                    m_selectedSources.push_back( curveDef.ensemble() );
+                    handleAddedSource( curveDef.ensemble() );
+                }
             }
         }
         else
         {
             if ( curveDef.summaryCase() && ( !curveDef.ensemble() || m_showIndividualEnsembleCases ) )
             {
-                m_selectedSources.push_back( curveDef.summaryCase() );
-                handleAddedSource( curveDef.summaryCase() );
+                if ( std::find( m_selectedSources.begin(), m_selectedSources.end(), curveDef.summaryCase() ) ==
+                     m_selectedSources.end() )
+                {
+                    m_selectedSources.push_back( curveDef.summaryCase() );
+                    handleAddedSource( curveDef.summaryCase() );
+                }
             }
         }