diff --git a/lcl/interfaces/win32/win32listsl.inc b/lcl/interfaces/win32/win32listsl.inc
index 8a6c9689ec..350a3966a2 100644
--- a/lcl/interfaces/win32/win32listsl.inc
+++ b/lcl/interfaces/win32/win32listsl.inc
@@ -373,7 +373,6 @@ begin
     inherited Assign(Source);
     
     // restore text in edit box
-    UpdateComboHeight;
     TWin32WSWinControl.SetText(FSender, EditText);
     if EditText = '' then
       lItemIndex := -1
@@ -420,6 +419,14 @@ begin
   SetWindowPos(FSender.Handle, 0, 0, 0, Width, Height, SWP_NOZORDER or SWP_NOACTIVATE or SWP_NOMOVE);
 end;
 
+procedure TWin32ComboBoxStringList.AddStrings(TheStrings: TStrings);
+begin
+  inherited AddStrings(TheStrings);
+
+  // Make sure dropdown etc is set correctly
+  UpdateComboHeight;
+end;
+
 procedure TWin32ComboBoxStringList.Clear;
 var
   SaveText: String;
diff --git a/lcl/interfaces/win32/win32listslh.inc b/lcl/interfaces/win32/win32listslh.inc
index cf167e95eb..26fb0c3c79 100644
--- a/lcl/interfaces/win32/win32listslh.inc
+++ b/lcl/interfaces/win32/win32listslh.inc
@@ -84,6 +84,7 @@ Type
     procedure InitFlags; override;
     procedure UpdateComboHeight;
   public
+    procedure AddStrings(TheStrings: TStrings); override;
     procedure Assign(Source: TPersistent); override;
     procedure Clear; override;
     procedure Delete(Index: integer); override;