diff --git a/src/generic/treectlg.cpp b/src/generic/treectlg.cpp
index 71f27e271d..edfa111639 100644
--- a/src/generic/treectlg.cpp
+++ b/src/generic/treectlg.cpp
@@ -665,6 +665,17 @@ bool wxGenericTreeCtrl::Create(wxWindow *parent,
                                const wxValidator &validator,
                                const wxString& name )
 {
+#ifdef __WXMAC__
+    int major,minor;
+    wxGetOsVersion( &major, &minor );
+    
+    if (style & wxTR_HAS_BUTTONS) style |= wxTR_MAC_BUTTONS;
+    style &= ~wxTR_LINES_AT_ROOT;
+    style |= wxTR_NO_LINES;
+    if (major < 10)
+        style |= wxTR_ROW_LINES;
+#endif
+
     wxScrolledWindow::Create( parent, id, pos, size,
                               style|wxHSCROLL|wxVSCROLL, name );
 
diff --git a/src/html/helpfrm.cpp b/src/html/helpfrm.cpp
index 2ca35f3f48..0f30f43339 100644
--- a/src/html/helpfrm.cpp
+++ b/src/html/helpfrm.cpp
@@ -346,13 +346,8 @@ bool wxHtmlHelpFrame::Create(wxWindow* parent, wxWindowID id,
 
 
             wxLayoutConstraints *b4 = new wxLayoutConstraints;
-            m_ContentsBox = new wxTreeCtrl(dummy, wxID_HTML_TREECTRL,
-                                           wxDefaultPosition, wxDefaultSize,
-#ifdef __WXMAC__
-       wxSUNKEN_BORDER|wxTR_MAC_BUTTONS|wxTR_NO_LINES|wxTR_ROW_LINES );
-#else
-       wxSUNKEN_BORDER|wxTR_HAS_BUTTONS );
-#endif
+            m_ContentsBox = new wxTreeCtrl( dummy, wxID_HTML_TREECTRL,
+                wxDefaultPosition, wxDefaultSize, wxSUNKEN_BORDER|wxTR_HAS_BUTTONS );
             m_ContentsBox->AssignImageList(ContentsImageList);
 
             b4->top.Below (m_Bookmarks, 10);