diff --git a/kicad/dialogs/dialog_template_selector.h b/kicad/dialogs/dialog_template_selector.h
index 74b14e06fb..93a03eaca2 100644
--- a/kicad/dialogs/dialog_template_selector.h
+++ b/kicad/dialogs/dialog_template_selector.h
@@ -2,7 +2,7 @@
  * This program source code file is part of KiCad, a free EDA CAD application.
  *
  * Copyright (C) 2012 Brian Sidebotham <brian.sidebotham@gmail.com>
- * Copyright (C) 1992-2012 KiCad Developers, see AUTHORS.txt for contributors.
+ * Copyright (C) 1992-2018 KiCad Developers, see AUTHORS.txt for contributors.
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -106,7 +106,7 @@ public:
 
 private:
 
-    void SetHtml( wxFileName aFilename )
+    void SetHtml( const wxFileName& aFilename )
     {
         m_htmlWin->LoadPage( aFilename.GetFullPath() );
     }
diff --git a/kicad/import_project.cpp b/kicad/import_project.cpp
index 62a6ab6216..4f9d043607 100644
--- a/kicad/import_project.cpp
+++ b/kicad/import_project.cpp
@@ -1,7 +1,7 @@
 /*
  * This program source code file is part of KiCad, a free EDA CAD application.
  *
- * Copyright (C) 2017 KiCad Developers, see AUTHORS.txt for contributors.
+ * Copyright (C) 2017-2018 KiCad Developers, see AUTHORS.txt for contributors.
  * @author Russell Oliver <roliver8143@gmail.com>
  *
  * This program is free software; you can redistribute it and/or
@@ -130,7 +130,7 @@ void KICAD_MANAGER_FRAME::OnImportEagleFiles( wxCommandEvent& event )
             {
                 schframe = Kiway.Player( FRAME_SCH, true );
             }
-            catch( IO_ERROR err )
+            catch( const IO_ERROR& err )
             {
                 wxMessageBox( _( "Eeschema failed to load:\n" ) + err.What(),
                         _( "KiCad Error" ), wxOK | wxICON_ERROR, this );
@@ -139,7 +139,8 @@ void KICAD_MANAGER_FRAME::OnImportEagleFiles( wxCommandEvent& event )
         }
 
         schframe->Kiway().ExpressMail( FRAME_SCH, MAIL_IMPORT_FILE,
-                wxString::Format( "%d\n%s", SCH_IO_MGR::SCH_EAGLE, sch.GetFullPath() ).ToStdString(), this );
+                wxString::Format( "%d\n%s", SCH_IO_MGR::SCH_EAGLE,
+                                  sch.GetFullPath() ).ToStdString(), this );
 
         if( !schframe->IsShown() )      // the frame exists, (created by the dialog field editor)
                                         // but no project loaded.
diff --git a/kicad/mainframe.cpp b/kicad/mainframe.cpp
index 21d6fda52f..899815b38f 100644
--- a/kicad/mainframe.cpp
+++ b/kicad/mainframe.cpp
@@ -3,7 +3,7 @@
  *
  * Copyright (C) 2017 Jean-Pierre Charras, jp.charras at wanadoo.fr
  * Copyright (C) 2013 CERN (www.cern.ch)
- * Copyright (C) 2004-2017 KiCad Developers, see change_log.txt for contributors.
+ * Copyright (C) 2004-2018 KiCad Developers, see change_log.txt for contributors.
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -311,7 +311,7 @@ void KICAD_MANAGER_FRAME::RunEeschema( const wxString& aProjectSchematicFileName
         {
             frame = Kiway.Player( FRAME_SCH, true );
         }
-        catch( IO_ERROR err )
+        catch( const IO_ERROR& err )
         {
             wxMessageBox( _( "Eeschema failed to load:\n" ) + err.What(),
                           _( "KiCad Error" ), wxOK | wxICON_ERROR, this );
@@ -358,7 +358,7 @@ void KICAD_MANAGER_FRAME::OnRunSchLibEditor( wxCommandEvent& event )
         {
             frame = Kiway.Player( FRAME_SCH_LIB_EDITOR, true );
         }
-        catch( IO_ERROR err )
+        catch( const IO_ERROR& err )
         {
             wxMessageBox( _( "Component library editor failed to load:\n" ) + err.What(),
                           _( "KiCad Error" ), wxOK | wxICON_ERROR, this );
@@ -384,7 +384,7 @@ void KICAD_MANAGER_FRAME::RunPcbNew( const wxString& aProjectBoardFileName )
     {
         frame = Kiway.Player( FRAME_PCB, true );
     }
-    catch( IO_ERROR err )
+    catch( const IO_ERROR& err )
     {
         wxMessageBox( _( "Pcbnew failed to load:\n" ) + err.What(), _( "KiCad Error" ),
                       wxOK | wxICON_ERROR, this );
@@ -430,7 +430,7 @@ void KICAD_MANAGER_FRAME::OnRunPcbFpEditor( wxCommandEvent& event )
         {
             frame = Kiway.Player( FRAME_PCB_MODULE_EDITOR, true );
         }
-        catch( IO_ERROR err )
+        catch( const IO_ERROR& err )
         {
             wxMessageBox( _( "Footprint library editor failed to load:\n" ) + err.What(),
                           _( "KiCad Error" ), wxOK | wxICON_ERROR, this );
diff --git a/lib_dxf/drw_entities.h b/lib_dxf/drw_entities.h
index a8e7f75a95..50ab4acf4a 100644
--- a/lib_dxf/drw_entities.h
+++ b/lib_dxf/drw_entities.h
@@ -647,7 +647,7 @@ public:
         }
     }
 
-    void addVertex( DRW_Vertex v )
+    void addVertex( const DRW_Vertex& v )
     {
         DRW_Vertex* vert = new DRW_Vertex();