diff --git a/lcl/include/customcombobox.inc b/lcl/include/customcombobox.inc
index 56e327c557..3a0070db6f 100644
--- a/lcl/include/customcombobox.inc
+++ b/lcl/include/customcombobox.inc
@@ -458,6 +458,23 @@ begin
   RegisterCustomComboBox;
 end;
 
+procedure TCustomComboBox.CreateParams(var Params: TCreateParams);
+const
+  ComboBoxStyles: array[TComboBoxStyle] of dword = (
+    CBS_DROPDOWN, CBS_SIMPLE, CBS_DROPDOWNLIST,
+    CBS_OWNERDRAWFIXED, CBS_OWNERDRAWVARIABLE);
+  ComboBoxReadOnlyStyles: array[boolean] of dword = (
+    CBS_DROPDOWN, CBS_DROPDOWNLIST);
+begin
+  inherited CreateParams(Params);
+  Params.Style := Params.Style or (WS_VSCROLL or CBS_AUTOHSCROLL or CBS_HASSTRINGS) or
+    ComboBoxStyles[Style];
+  if Style in [csOwnerDrawFixed, csOwnerDrawVariable] then
+    Params.Style := Params.Style or ComboBoxReadOnlyStyles[ReadOnly];
+  if Sorted then
+    Params.Style := Params.Style or CBS_SORT;
+end;
+
 procedure TCustomComboBox.KeyDown(var Key: Word; Shift: TShiftState);
 var
   skip : Boolean;
diff --git a/lcl/interfaces/win32/win32wsstdctrls.pp b/lcl/interfaces/win32/win32wsstdctrls.pp
index c32c3318e1..d28b99522f 100644
--- a/lcl/interfaces/win32/win32wsstdctrls.pp
+++ b/lcl/interfaces/win32/win32wsstdctrls.pp
@@ -761,18 +761,14 @@ begin
   // customization of Params
   with Params do
   begin
-    Flags := Flags or CalcComboBoxWinFlags(TCustomComboBox(AWinControl));
-    if TComboBox(AWinControl).Sorted Then
-      Flags:= Flags or CBS_SORT;
     pClassName := ComboboxClsName;
     pSubClassName := LCLComboboxClsName;
-    Flags := Flags or (WS_VSCROLL or CBS_AUTOHSCROLL or CBS_HASSTRINGS);
     SubClassWndProc := @ComboBoxWindowProc;
   end;
   // create window
   FinishCreateWindow(AWinControl, Params, False, True);
 
-  Info.cbSize:= SizeOf(Info);
+  Info.cbSize := SizeOf(Info);
   Win32Extra.GetComboBoxInfo(Params.Window, @Info);
 
   // get edit window within
diff --git a/lcl/interfaces/wince/wincewsstdctrls.pp b/lcl/interfaces/wince/wincewsstdctrls.pp
index 93d89a9b7d..6d620584f1 100644
--- a/lcl/interfaces/wince/wincewsstdctrls.pp
+++ b/lcl/interfaces/wince/wincewsstdctrls.pp
@@ -640,11 +640,9 @@ begin
   // customization of Params
   with Params do
   begin
-    Flags := Flags or CalcComboBoxWinFlags(TCustomComboBox(AWinControl));
-    If TComboBox(AWinControl).Sorted Then
-      Flags:= Flags or CBS_SORT;
+    // remove unsupported styles
+    Flags := Flags and not (CBS_SIMPLE or CBS_OWNERDRAWFIXED or CBS_OWNERDRAWVARIABLE);
     pClassName := @ComboboxClsName;
-    Flags := Flags or (WS_VSCROLL or CBS_AUTOHSCROLL or CBS_HASSTRINGS);
     SubClassWndProc := @ComboBoxWindowProc;
   end;
   // create window
diff --git a/lcl/lcltype.pp b/lcl/lcltype.pp
index fea6d0b0c4..de3ab0751c 100644
--- a/lcl/lcltype.pp
+++ b/lcl/lcltype.pp
@@ -924,6 +924,16 @@ const
   ES_READONLY      = $0800;
   ES_WANTRETURN    = $1000;
 
+  { Combobox style }
+  CBS_SIMPLE            = $0001;
+  CBS_DROPDOWN          = $0002;
+  CBS_DROPDOWNLIST      = $0003;
+  CBS_OWNERDRAWFIXED    = $0010;
+  CBS_OWNERDRAWVARIABLE = $0020;
+  CBS_AUTOHSCROLL       = $0040;
+  CBS_SORT              = $0100;
+  CBS_HASSTRINGS        = $0200;
+
 const
 //==============================================
 // SetWindowPos Flags
diff --git a/lcl/stdctrls.pp b/lcl/stdctrls.pp
index 80c47971ed..b3dfe313fa 100644
--- a/lcl/stdctrls.pp
+++ b/lcl/stdctrls.pp
@@ -302,6 +302,7 @@ type
     procedure SetCharCase(eccCharCase: TEditCharCase);
   protected
     class procedure WSRegisterClass; override;
+    procedure CreateParams(var Params: TCreateParams); override;
     procedure InitializeWnd; override;
     procedure DestroyWnd; override;
     procedure DoEnter; override;