diff --git a/src/html/helpwnd.cpp b/src/html/helpwnd.cpp
index 45b337ed66..ab52ea8743 100644
--- a/src/html/helpwnd.cpp
+++ b/src/html/helpwnd.cpp
@@ -1230,9 +1230,19 @@ public:
 
         topsizer->Add(new wxStaticText(this, wxID_ANY, _("Preview:")),
                         0, wxLEFT | wxTOP, 10);
+
+        int style = wxHW_SCROLLBAR_AUTO;
+
+#ifdef __WXMSW__
+        style |= GetThemedBorderStyle();
+#else
+        style |= wxBORDER_SUNKEN;
+#endif
+        topsizer->AddSpacer(5);
+
         topsizer->Add(TestWin = new wxHtmlWindow(this, wxID_ANY, wxDefaultPosition, wxSize(20, 150),
-                                                 wxHW_SCROLLBAR_AUTO | wxSUNKEN_BORDER),
-                        1, wxEXPAND | wxLEFT|wxTOP|wxRIGHT, 10);
+                                                 style),
+                        1, wxEXPAND | wxLEFT|wxRIGHT, 10);
 
         wxBoxSizer *sizer2 = new wxBoxSizer(wxHORIZONTAL);
         wxButton *ok;