diff --git a/components/tvplanit/source/vpevnteditdlg.lfm b/components/tvplanit/source/vpevnteditdlg.lfm
index 94acb14e3..a7a6c76f1 100644
--- a/components/tvplanit/source/vpevnteditdlg.lfm
+++ b/components/tvplanit/source/vpevnteditdlg.lfm
@@ -286,13 +286,11 @@ object DlgEventEdit: TDlgEventEdit
     end
     object Category: TComboBox
       Left = 484
-      Height = 21
+      Height = 23
       Top = 40
       Width = 180
       ItemHeight = 15
       OnDrawItem = CategoryDrawItem
-      ReadOnly = True
-      Style = csOwnerDrawFixed
       TabOrder = 2
     end
     object RecurringType: TComboBox
diff --git a/components/tvplanit/source/vpevnteditdlg.pas b/components/tvplanit/source/vpevnteditdlg.pas
index fe57a67e0..c2b84f627 100644
--- a/components/tvplanit/source/vpevnteditdlg.pas
+++ b/components/tvplanit/source/vpevnteditdlg.pas
@@ -199,6 +199,8 @@ end;
 { TDlgEventEdit }
 
 procedure TDlgEventEdit.FormCreate(Sender: TObject);
+var
+  h: Integer;
 begin
  {$IFDEF LCL}
   StartTime := TTimeEdit.Create(self);
@@ -246,7 +248,13 @@ begin
   end;
   IntervalUpDown.Associate := FCustomInterval;
 
-  Category.ItemHeight := LocationEdit.Height - 6;
+  // This is needed as workaround for the combobox height at higher dpi.
+  // We design it with Style csDropdown where the height is correct, and then
+  // use the corresponding, correct ItemHeight after switching to csOwnerDrawFixed
+  // (which is needed to draw the color boxes).
+  h := Category.ItemHeight;
+  Category.Style := csOwnerDrawFixed;
+  Category.ItemHeight := h;
 end;
 {=====}