diff --git a/lcl/interfaces/gtk/gtkwinapi.inc b/lcl/interfaces/gtk/gtkwinapi.inc
index 9411cb9a36..cc74ea866d 100644
--- a/lcl/interfaces/gtk/gtkwinapi.inc
+++ b/lcl/interfaces/gtk/gtkwinapi.inc
@@ -2272,7 +2272,12 @@ function TGtkWidgetSet.ComboBoxDropDown(Handle: HWND; DropDown: boolean): boolea
     avail_height := gdk_screen_height () - y;
 
     New(list_requisition);
-    gtk_widget_size_request (combo^.list, list_requisition);
+    if combo^.list<>nil then begin
+      gtk_widget_size_request (combo^.list, list_requisition);
+    end else begin
+      list_requisition^.height:=1;
+      list_requisition^.width:=1;
+    end;
 
     min_height := MIN (list_requisition^.height,popup^.vscrollbar^.requisition.height);
     if  GTK_LIST (combo^.list)^.children = nil then
@@ -8429,9 +8434,13 @@ begin
     FirstChild:=PGTkList(ListWidget)^.children;
     if FirstChild<>nil then begin
       FirstChildWidget:=PGtkWidget(FirstChild^.Data);
-      gtk_widget_size_request(FirstChildWidget,@item_requisition);
-      CurItemHeight:=Max(FirstChildWidget^.Allocation.Height,
-                         item_requisition.Height);
+      if FirstChildWidget<>nil then begin
+        gtk_widget_size_request(FirstChildWidget,@item_requisition);
+        CurItemHeight:=Max(FirstChildWidget^.Allocation.Height,
+                           item_requisition.Height);
+      end else begin
+        CurItemHeight:=1;
+      end;
       if MinItemsHeight<CurItemHeight*MinItemCount then
         MinItemsHeight:=CurItemHeight*MinItemCount;
     end;
diff --git a/lcl/interfaces/gtk/gtkwsstdctrls.pp b/lcl/interfaces/gtk/gtkwsstdctrls.pp
index a376c07c46..fac9403e7f 100644
--- a/lcl/interfaces/gtk/gtkwsstdctrls.pp
+++ b/lcl/interfaces/gtk/gtkwsstdctrls.pp
@@ -613,8 +613,10 @@ begin
   while GListItem<>nil do begin
     ListItemWidget:=PGtkWidget(GListItem^.data);
     if i>=NewTopIndex then break;
-    gtk_widget_size_request(ListItemWidget,@requisition);
-    inc(AdjValue,requisition.height);
+    if ListItemWidget<>nil then begin
+      gtk_widget_size_request(ListItemWidget,@requisition);
+      inc(AdjValue,requisition.height);
+    end;
     //DebugLn(['TGtkWSCustomListBox.SetTopIndex ',i,' AdjValue=',AdjValue,' Flags=',WidgetFlagsToString(ListItemWidget)]);
     inc(i);
     GListItem:=GListItem^.next;
diff --git a/lcl/interfaces/gtk2/gtk2lclintf.inc b/lcl/interfaces/gtk2/gtk2lclintf.inc
index f43f936f7a..3849c117e7 100644
--- a/lcl/interfaces/gtk2/gtk2lclintf.inc
+++ b/lcl/interfaces/gtk2/gtk2lclintf.inc
@@ -71,10 +71,11 @@ begin
   p := GetWidgetInfo(Pointer(Handle), False)^.CoreWidget;
   
   Menu := PGtkWidget(g_object_get_data(G_OBJECT(p), 'Menu'));
-
-  Requisition.width := MinItemsWidth;
-  Requisition.height := MinItemsHeight * MinItemCount;
-  gtk_widget_size_request(Menu, @Requisition);
+  if Menu<>nil then begin
+    Requisition.width := MinItemsWidth;
+    Requisition.height := MinItemsHeight * MinItemCount;
+    gtk_widget_size_request(Menu, @Requisition);
+  end;
 end;
 
 //##apiwiz##eps##   // Do not remove, no wizard declaration after this line