diff --git a/lcl/interfaces/gtk/gtkcallback.inc b/lcl/interfaces/gtk/gtkcallback.inc
index b8531f100e..6e8222e122 100644
--- a/lcl/interfaces/gtk/gtkcallback.inc
+++ b/lcl/interfaces/gtk/gtkcallback.inc
@@ -632,7 +632,8 @@ end;
 function gtkfrmactivateAfter(widget: PGtkWidget; Event : PgdkEventFocus;
   data: gPointer) : GBoolean; cdecl;
 var
-  Mess : TLMActivate;
+  Mess: TLMActivate;
+  Info: PWidgetInfo;
 {$IFDEF VerboseFocus}
   LCLObject: TObject;
   CurFocusWidget: PGtkWidget;
@@ -677,14 +678,22 @@ begin
   DebugLn('');
   {$ENDIF}
 
-  Mess.Msg := LM_ACTIVATE;
-  Mess.Active:=true;
-  Mess.Minimized:=false;
-  Mess.ActiveWindow:=0;
-  if GtkWidgetIsA(Widget, gtk_window_get_type) then
-    Mess.ActiveWindow:=HWnd(PtrUInt(PGTKWindow(Widget)^.focus_widget));
-  Mess.Result := 0;
-  DeliverMessage(Data, Mess); // send message directly (not Post)
+  Info := GetWidgetInfo(Widget, false);
+  try
+    if (Info <> nil) then
+      Include(Info^.Flags, wwiActivating);
+    Mess.Msg := LM_ACTIVATE;
+    Mess.Active := True;
+    Mess.Minimized := False;
+    Mess.ActiveWindow := 0;
+    if GtkWidgetIsA(Widget, gtk_window_get_type) then
+      Mess.ActiveWindow := HWnd(PtrUInt(PGTKWindow(Widget)^.focus_widget));
+    Mess.Result := 0;
+    DeliverMessage(Data, Mess); // send message directly (not Post)
+  finally
+    if Info <> nil then
+      Exclude(Info^.Flags, wwiActivating);
+  end;
 
   Result := CallBackDefaultReturn;
 end;
@@ -692,7 +701,7 @@ end;
 function gtkfrmdeactivateAfter( widget: PGtkWidget; Event : PgdkEventFocus;
   data: gPointer) : GBoolean; cdecl;
 var
-  Mess : TLMActivate;
+  Mess: TLMActivate;
   Info: PWidgetInfo;
 {$IFDEF VerboseFocus}
   LCLObject: TControl;
diff --git a/lcl/interfaces/gtk/gtkdef.pp b/lcl/interfaces/gtk/gtkdef.pp
index 6a82b03dad..b5a28642a9 100644
--- a/lcl/interfaces/gtk/gtkdef.pp
+++ b/lcl/interfaces/gtk/gtkdef.pp
@@ -412,7 +412,8 @@ type
     wwiNotOnParentsClientArea,
     wwiValidQueuedEvent,              // Mark this widgetinfo as valid queued proc
                                       // see gtkwsmenus.pp: gtkWSPopupMenuDeactivate
-    wwiDeactivating    // during gtk deactivate
+    wwiDeactivating,                  // during gtk deactivate
+    wwiActivating                     // during gtk activate
     );
   TWidgetInfoFlags = set of TWidgetInfoFlag;
   tGtkStateEnumRange = 0..31;
diff --git a/lcl/interfaces/gtk/gtkwinapi.inc b/lcl/interfaces/gtk/gtkwinapi.inc
index bb45eadb6a..54e2f74b11 100644
--- a/lcl/interfaces/gtk/gtkwinapi.inc
+++ b/lcl/interfaces/gtk/gtkwinapi.inc
@@ -8603,6 +8603,7 @@ function TGtkWidgetSet.SetFocus(hWnd: HWND): HWND;
 {off $DEFINE VerboseFocus}
 var
   Widget, TopLevel, NewFocusWidget: PGtkWidget;
+  Info: PWidgetInfo;
   {$IfDef VerboseFocus}
   AWinControl: TWinControl;
   {$EndIf}
@@ -8623,7 +8624,7 @@ begin
 
   // return the old focus handle
   Result := GetFocus;
-  NewFocusWidget:=nil;
+  NewFocusWidget := nil;
 
   TopLevel := gtk_widget_get_toplevel(Widget);
   {$IfDef VerboseFocus}
@@ -8662,9 +8663,7 @@ begin
         DebugLn('  there is a modal form above -> focus forbidden');
         {$EndIf}
         exit;
-      end{
-      else
-        SetForegroundWindow(NewForm.Handle)};
+      end;
     end;
 
     NewFocusWidget := FindFocusWidget(Widget);
@@ -8678,14 +8677,15 @@ begin
     write(' TopLvlVisible=',GTK_WIDGET_VISIBLE(PGtkWidget(TopLevel)));
     DebugLn('');
     {$EndIf}
-    if (NewFocusWidget<>nil) and GTK_WIDGET_CAN_FOCUS(NewFocusWidget) then begin
-      if (PGtkWindow(TopLevel)^.Focus_Widget<>NewFocusWidget)
-      then begin
+    if (NewFocusWidget<>nil) and GTK_WIDGET_CAN_FOCUS(NewFocusWidget) then
+    begin
+      if (PGtkWindow(TopLevel)^.Focus_Widget<>NewFocusWidget) then
+      begin
         {$IfDef VerboseFocus}
         DebugLn('  H SETTING NewFocusWidget=',dbgs(NewFocusWidget),' ',DbgSName(GetNearestLCLObject(NewFocusWidget)));
         {$EndIf}
         //DebugLn('TGtkWidgetSet.SetFocus TopLevel[',DebugGtkWidgets.GetInfo(TopLevel,false),'] NewFocusWidget=[',DebugGtkWidgets.GetInfo(NewFocusWidget,false),']');
-        gtk_window_set_focus(PGtkWindow(TopLevel),NewFocusWidget);
+        gtk_window_set_focus(PGtkWindow(TopLevel), NewFocusWidget);
         {$IfDef VerboseFocus}
         DebugLn('  I NewTopLevel FocusWidget=',DbgS(PGtkWindow(TopLevel)^.Focus_Widget),' Success=',dbgs(PGtkWindow(TopLevel)^.Focus_Widget=NewFocusWidget));
         {$EndIf}
@@ -8700,9 +8700,10 @@ begin
   begin
     // grab the focus to the parent window
     NewTopLevelWidget := gtk_widget_get_toplevel(NewFocusWidget);
+    NewTopLevelObject := GetNearestLCLObject(NewTopLevelWidget);
     if (Screen<>nil)
     and (Screen.GetCurrentModalForm<>nil)
-    and (GetNearestLCLObject(NewTopLevelWidget)<>Screen.GetCurrentModalForm)
+    and (NewTopLevelObject <>Screen.GetCurrentModalForm)
     then begin
       {$IFDEF VerboseFocus}
       DebugLn('[TGtkWidgetSet.SetFocus] there is a modal form -> not grabbing');
@@ -8711,6 +8712,12 @@ begin
       {$IfDef VerboseFocus}
       DebugLn('  J Grabbing focus ',GetWidgetDebugReport(NewFocusWidget));
       {$EndIf}
+      if NewTopLevelObject is TCustomForm then
+      begin
+        Info := GetWidgetInfo(NewTopLevelWidget, False);
+        if (Info <> nil) and not (wwiActivating in  Info^.Flags) then
+          SetForegroundWindow(TCustomForm(NewTopLevelObject).Handle);
+      end;
       gtk_widget_grab_focus(NewFocusWidget);
     end;
   end;