diff --git a/eeschema/netlist_exporters/netlist_exporter_pspice.cpp b/eeschema/netlist_exporters/netlist_exporter_pspice.cpp
index d8f96d097a..174fbffffe 100644
--- a/eeschema/netlist_exporters/netlist_exporter_pspice.cpp
+++ b/eeschema/netlist_exporters/netlist_exporter_pspice.cpp
@@ -52,7 +52,8 @@ bool NETLIST_EXPORTER_PSPICE::Format( OUTPUTFORMATTER* aFormatter, unsigned aCtl
     // Netlist options
     const bool useNetcodeAsNetName = aCtl & NET_USE_NETCODES_AS_NETNAMES;
 
-    ProcessNetlist( aCtl );
+    if( !ProcessNetlist( aCtl ) )
+        return false;
 
     aFormatter->Print( 0, ".title KiCad schematic\n" );
 
@@ -234,10 +235,12 @@ wxString NETLIST_EXPORTER_PSPICE::GetSpiceFieldDefVal( SPICE_FIELD aField,
 }
 
 
-void NETLIST_EXPORTER_PSPICE::ProcessNetlist( unsigned aCtl )
+bool NETLIST_EXPORTER_PSPICE::ProcessNetlist( unsigned aCtl )
 {
     const wxString      delimiters( "{:,; }" );
     SCH_SHEET_LIST      sheetList( g_RootSheet );
+    // Set of reference names, to check for duplications
+    std::set<wxString>  refNames;
 
     // Prepare list of nets generation (not used here, but...
     for( unsigned ii = 0; ii < m_masterList->size(); ii++ )
@@ -275,6 +278,16 @@ void NETLIST_EXPORTER_PSPICE::ProcessNetlist( unsigned aCtl )
             spiceItem.m_model = GetSpiceField( SF_MODEL, comp, aCtl );
             spiceItem.m_refName = comp->GetRef( &sheetList[sheet_idx] );
 
+            // Duplicate references will result in simulation errors
+            if( refNames.count( spiceItem.m_refName ) )
+            {
+                DisplayError( NULL, wxT( "There are duplicate components. "
+                            "You need to annotate schematics first." ) );
+                return false;
+            }
+
+            refNames.insert( spiceItem.m_refName );
+
             // Check to see if component should be removed from Spice netlist
             spiceItem.m_enabled = StringToBool( GetSpiceField( SF_ENABLED, comp, aCtl ) );
 
@@ -326,6 +339,8 @@ void NETLIST_EXPORTER_PSPICE::ProcessNetlist( unsigned aCtl )
             m_spiceItems.push_back( spiceItem );
         }
     }
+
+    return true;
 }
 
 
diff --git a/eeschema/netlist_exporters/netlist_exporter_pspice.h b/eeschema/netlist_exporters/netlist_exporter_pspice.h
index d0407912fc..44d4ed6d10 100644
--- a/eeschema/netlist_exporters/netlist_exporter_pspice.h
+++ b/eeschema/netlist_exporters/netlist_exporter_pspice.h
@@ -113,7 +113,13 @@ public:
 
     bool Format( OUTPUTFORMATTER* aFormatter, unsigned aCtl );
 
-    void ProcessNetlist( unsigned aCtl );
+    /**
+     * @brief Processes the netlist to create net mapping and a list of SPICE_ITEMs.
+     * It is automatically called by WriteNetlist(), but might be used separately,
+     * if only net mapping and the list of SPICE_ITEMs are required.
+     * @return True if successful.
+     */
+    bool ProcessNetlist( unsigned aCtl );
 
     const NET_INDEX_MAP& GetNetIndexMap() const
     {
diff --git a/eeschema/sim/sim_plot_frame.cpp b/eeschema/sim/sim_plot_frame.cpp
index d3f0f7b6c1..772a6c365e 100644
--- a/eeschema/sim/sim_plot_frame.cpp
+++ b/eeschema/sim/sim_plot_frame.cpp
@@ -150,11 +150,16 @@ void SIM_PLOT_FRAME::StartSimulation()
 
     updateNetlistExporter();
     m_exporter->SetSimCommand( m_settingsDlg.GetSimCommand() );
-    m_exporter->Format( &formatter, m_settingsDlg.GetNetlistOptions() );
+
+    if( !m_exporter->Format( &formatter, m_settingsDlg.GetNetlistOptions() ) )
+    {
+        DisplayError( this, wxT( "There were errors during netlist export, aborted." ) );
+        return;
+    }
 
     if( m_exporter->GetSimType() == ST_UNKNOWN )
     {
-        DisplayInfoMessage( this, wxT( "You need to select the simulation settings first" ) );
+        DisplayInfoMessage( this, wxT( "You need to select the simulation settings first." ) );
         return;
     }
 
@@ -647,8 +652,15 @@ void SIM_PLOT_FRAME::onSimulate( wxCommandEvent& event )
 
 void SIM_PLOT_FRAME::onSettings( wxCommandEvent& event )
 {
+    // Initial processing is required to e.g. display a list of power sources
     updateNetlistExporter();
-    m_exporter->ProcessNetlist( NET_ALL_FLAGS );
+
+    if( !m_exporter->ProcessNetlist( NET_ALL_FLAGS ) )
+    {
+        DisplayError( this, wxT( "There were errors during netlist export, aborted." ) );
+        return;
+    }
+
     m_settingsDlg.SetNetlistExporter( m_exporter.get() );
     m_settingsDlg.ShowModal();
 }
@@ -660,7 +672,7 @@ void SIM_PLOT_FRAME::onAddSignal( wxCommandEvent& event )
 
     if( !plotPanel || !m_exporter || plotPanel->GetType() != m_exporter->GetSimType() )
     {
-        DisplayInfoMessage( this, wxT( "You need to run simulation first" ) );
+        DisplayInfoMessage( this, wxT( "You need to run simulation first." ) );
         return;
     }