diff --git a/lcl/comctrls.pp b/lcl/comctrls.pp
index 72925fc53d..18f05f8b59 100644
--- a/lcl/comctrls.pp
+++ b/lcl/comctrls.pp
@@ -374,7 +374,6 @@ type
     function  DialogChar(var Message: TLMKey): boolean; override;
     procedure ShowControl(APage: TControl); override;
     procedure UpdateTabProperties; virtual;
-    function ChildClassAllowed(ChildClass: TClass): boolean; override;
     class function GetControlClassDefaultSize: TSize; override;
     procedure Notification(AComponent: TComponent; Operation: TOperation); override;
     property ActivePageComponent: TCustomPage read GetActivePageComponent
@@ -510,6 +509,7 @@ type
     procedure DoRemoveDockClient(Client: TControl); override;
     function DoUndockClientMsg(NewTarget, Client: TControl):boolean; override;
     procedure DoChange; override;
+    function ChildClassAllowed(ChildClass: TClass): boolean; override;
   public
     constructor Create(TheOwner: TComponent); override;
     function FindNextPage(CurPage: TTabSheet;
@@ -806,6 +806,8 @@ type
     property Visible;
   end;
 
+{$ifdef LCL_NEW_TABCONTROL}
+
   { TNewTabControl }
 
 (* TNewTabControl is a replacement for TTabControl, derived from TCustomTabControl.
@@ -881,6 +883,8 @@ type
     property Visible;
   end;
 
+{$endif}
+
   { Custom draw }
 
   TCustomDrawTarget = (
@@ -3452,7 +3456,9 @@ end;
 procedure Register;
 begin
   RegisterComponents('Common Controls',[TTrackbar,TProgressBar,TTreeView,
-    TListView,TStatusBar,TToolBar,TUpDown,TPageControl,TTabControl,THeaderControl]);
+    TListView,TStatusBar,TToolBar,TUpDown,TPageControl,TTabControl,
+{$ifdef LCL_NEW_TABCONTROL}TNewTabControl,{$endif}
+    THeaderControl]);
   RegisterNoIcon([TToolButton,TTabSheet]);
 end;
 
diff --git a/lcl/include/customnotebook.inc b/lcl/include/customnotebook.inc
index b66ab8fde4..4cc0fe2990 100644
--- a/lcl/include/customnotebook.inc
+++ b/lcl/include/customnotebook.inc
@@ -874,11 +874,6 @@ begin
     TWSCustomPageClass(Page[i].WidgetSetClass).UpdateProperties(Page[i]);
 end;
 
-function TCustomTabControl.ChildClassAllowed(ChildClass: TClass): boolean;
-begin
-  Result:=(ChildClass<>nil) and (ChildClass.InheritsFrom(PageClass));
-end;
-
 class function TCustomTabControl.GetControlClassDefaultSize: TSize;
 begin
   Result.CX := 200;
diff --git a/lcl/include/pagecontrol.inc b/lcl/include/pagecontrol.inc
index f2c409a186..166e6bbb3c 100644
--- a/lcl/include/pagecontrol.inc
+++ b/lcl/include/pagecontrol.inc
@@ -115,6 +115,11 @@ begin
     OnChange(Self);
 end;
 
+function TPageControl.ChildClassAllowed(ChildClass: TClass): boolean;
+begin
+  Result:=(ChildClass<>nil) and (ChildClass.InheritsFrom(PageClass));
+end;
+
 constructor TPageControl.Create(TheOwner: TComponent);
 begin
   PageClass:=TTabSheet;
diff --git a/lcl/include/tabcontrol.inc b/lcl/include/tabcontrol.inc
index 0d5a03b1fc..d15989559b 100644
--- a/lcl/include/tabcontrol.inc
+++ b/lcl/include/tabcontrol.inc
@@ -689,6 +689,8 @@ begin
   Result:=(FTabs<>nil) and TTabControlStrings(fTabs).IsUpdating;
 end;
 
+{$ifdef LCL_NEW_TABCONTROL}
+
 { TTabPage }
 
 type
@@ -838,6 +840,7 @@ begin
       Dec(FPageIndex);
   end;
 end;
+{$endif}
 
 // included by comctrls.pp