diff --git a/contrib/src/gizmos/splittree.cpp b/contrib/src/gizmos/splittree.cpp
index 8cc478e706..17dfbe315b 100644
--- a/contrib/src/gizmos/splittree.cpp
+++ b/contrib/src/gizmos/splittree.cpp
@@ -377,7 +377,7 @@ void wxRemotelyScrolledTreeCtrl::AdjustRemoteScrollbars()
         if (scrolledWindow)
         {
             wxRect itemRect;
-            if (GetBoundingRect(GetFirstVisibleItem(), itemRect))
+            if (GetBoundingRect(GetRootItem(), itemRect))
             {
                 // Actually, the real height seems to be 1 less than reported
                 // (e.g. 16 instead of 16)