diff --git a/src/GUI/new_gui.cxx b/src/GUI/new_gui.cxx
index e99c15f92..04b0d4473 100644
--- a/src/GUI/new_gui.cxx
+++ b/src/GUI/new_gui.cxx
@@ -433,6 +433,9 @@ NewGUI::setStyle (void)
     
     SGPropertyNode *selected_style = globals->get_props()->getNode("sim/gui/selected-style", true);
 
+    // n->copy() doesn't delete existing nodes, so need to clear them all
+    // first.
+    selected_style->removeAllChildren();
     n->copy(selected_style);
 
     //if (selected_style && n)