diff --git a/kicad/project_tree.cpp b/kicad/project_tree.cpp
index f3e39a57bd..63fe484bbc 100644
--- a/kicad/project_tree.cpp
+++ b/kicad/project_tree.cpp
@@ -77,6 +77,7 @@ PROJECT_TREE::PROJECT_TREE( PROJECT_TREE_PANE* parent ) :
     m_imageList->Add( KiBitmap( module_xpm ) );                 // TREE_FOOTPRINT_FILE
     m_imageList->Add( KiBitmap( library_xpm ) );                // TREE_SCHEMATIC_LIBFILE
     m_imageList->Add( KiBitmap( library_xpm ) );                // TREE_SEXPR_SYMBOL_LIB_FILE
+    m_imageList->Add( KiBitmap( editor_xpm ) );                 // DESIGN_RULES
 
     SetImageList( m_imageList );
 }
diff --git a/kicad/project_tree_pane.cpp b/kicad/project_tree_pane.cpp
index e6b97d55b6..b02b802e50 100644
--- a/kicad/project_tree_pane.cpp
+++ b/kicad/project_tree_pane.cpp
@@ -285,6 +285,7 @@ wxString PROJECT_TREE_PANE::GetFileExt( TREE_FILE_TYPE type )
     case TREE_FILE_TYPE::FOOTPRINT_FILE:        return KiCadFootprintFileExtension;
     case TREE_FILE_TYPE::SCHEMATIC_LIBFILE:     return LegacySymbolLibFileExtension;
     case TREE_FILE_TYPE::SEXPR_SYMBOL_LIB_FILE: return KiCadSymbolLibFileExtension;
+    case TREE_FILE_TYPE::DESIGN_RULES:          return DesignRulesFileExtension;
     default:                                    return wxEmptyString;
     }
 }
diff --git a/kicad/tree_file_type.h b/kicad/tree_file_type.h
index 6c01469250..90195ec447 100644
--- a/kicad/tree_file_type.h
+++ b/kicad/tree_file_type.h
@@ -58,6 +58,7 @@ enum class TREE_FILE_TYPE
     FOOTPRINT_FILE,        // footprint file (.kicad_mod)
     SCHEMATIC_LIBFILE,     // schematic library file (.lib)
     SEXPR_SYMBOL_LIB_FILE, // s-expression symbol library file (.kicad_sym)
+    DESIGN_RULES,          // design rules (.kicad_dru)
     MAX
 };