diff --git a/pcbnew/pcb_edit_frame.cpp b/pcbnew/pcb_edit_frame.cpp
index 5c08cf063a..478fcfa257 100644
--- a/pcbnew/pcb_edit_frame.cpp
+++ b/pcbnew/pcb_edit_frame.cpp
@@ -306,6 +306,13 @@ PCB_EDIT_FRAME::PCB_EDIT_FRAME( KIWAY* aKiway, wxWindow* aParent ) :
     m_Layers = nullptr;
     m_FrameSize = ConvertDialogToPixels( wxSize( 500, 350 ) );    // default in case of no prefs
 
+    m_previous_requested_scale = 0;
+    m_previous_active_layer_color = COLOR4D::UNSPECIFIED;
+    m_previous_Route_Layer_TOP_color = COLOR4D::UNSPECIFIED;
+    m_previous_Route_Layer_BOTTOM_color = COLOR4D::UNSPECIFIED;
+    m_previous_via_color = COLOR4D::UNSPECIFIED;
+    m_previous_background_color = COLOR4D::UNSPECIFIED;
+
     // We don't know what state board was in when it was lasat saved, so we have to
     // assume dirty
     m_ZoneFillsDirty = true;
diff --git a/pcbnew/pcb_edit_frame.h b/pcbnew/pcb_edit_frame.h
index a916893b27..d27551cb00 100644
--- a/pcbnew/pcb_edit_frame.h
+++ b/pcbnew/pcb_edit_frame.h
@@ -100,6 +100,14 @@ protected:
 
     wxString          m_lastNetListRead;        ///< Last net list read with relative path.
 
+    // For PrepareLayerIndicator():
+    int     m_previous_requested_scale;
+    COLOR4D m_previous_active_layer_color;
+    COLOR4D m_previous_Route_Layer_TOP_color;
+    COLOR4D m_previous_Route_Layer_BOTTOM_color;
+    COLOR4D m_previous_via_color;
+    COLOR4D m_previous_background_color;
+
     // The Tool Framework initalization
     void setupTools();
 
diff --git a/pcbnew/tool_pcb_editor.cpp b/pcbnew/tool_pcb_editor.cpp
index 5428b8276d..c7dbdc645a 100644
--- a/pcbnew/tool_pcb_editor.cpp
+++ b/pcbnew/tool_pcb_editor.cpp
@@ -98,60 +98,55 @@ void PCB_EDIT_FRAME::PrepareLayerIndicator()
                Route_Layer_BOTTOM_color, via_color, background_color;
     bool       change = false;
 
-    static int previous_requested_scale;
-    static COLOR4D previous_active_layer_color, previous_Route_Layer_TOP_color,
-                   previous_Route_Layer_BOTTOM_color, previous_via_color,
-                   previous_background_color;
-
     int requested_scale;
     Pgm().CommonSettings()->Read( ICON_SCALE_KEY, &requested_scale, 0 );
 
-    if( requested_scale != previous_requested_scale )
+    if( requested_scale != m_previous_requested_scale )
     {
-        previous_requested_scale = requested_scale;
+        m_previous_requested_scale = requested_scale;
         change = true;
     }
 
     active_layer_color = Settings().Colors().GetLayerColor(GetActiveLayer());
 
-    if( previous_active_layer_color != active_layer_color )
+    if( m_previous_active_layer_color != active_layer_color )
     {
-        previous_active_layer_color = active_layer_color;
+        m_previous_active_layer_color = active_layer_color;
         change = true;
     }
 
     Route_Layer_TOP_color =
         Settings().Colors().GetLayerColor( GetScreen()->m_Route_Layer_TOP );
 
-    if( previous_Route_Layer_TOP_color != Route_Layer_TOP_color )
+    if( m_previous_Route_Layer_TOP_color != Route_Layer_TOP_color )
     {
-        previous_Route_Layer_TOP_color = Route_Layer_TOP_color;
+        m_previous_Route_Layer_TOP_color = Route_Layer_TOP_color;
         change = true;
     }
 
     Route_Layer_BOTTOM_color =
         Settings().Colors().GetLayerColor( GetScreen()->m_Route_Layer_BOTTOM );
 
-    if( previous_Route_Layer_BOTTOM_color != Route_Layer_BOTTOM_color )
+    if( m_previous_Route_Layer_BOTTOM_color != Route_Layer_BOTTOM_color )
     {
-        previous_Route_Layer_BOTTOM_color = Route_Layer_BOTTOM_color;
+        m_previous_Route_Layer_BOTTOM_color = Route_Layer_BOTTOM_color;
         change = true;
     }
 
     int via_type = GetDesignSettings().m_CurrentViaType;
     via_color = Settings().Colors().GetItemColor( LAYER_VIAS + via_type );
 
-    if( previous_via_color != via_color )
+    if( m_previous_via_color != via_color )
     {
-        previous_via_color = via_color;
+        m_previous_via_color = via_color;
         change = true;
     }
 
     background_color = Settings().Colors().GetItemColor( LAYER_PCB_BACKGROUND );
 
-    if( previous_background_color != background_color )
+    if( m_previous_background_color != background_color )
     {
-        previous_background_color = background_color;
+        m_previous_background_color = background_color;
         change = true;
     }