diff --git a/neo/tools/compilers/aas/BrushBSP.cpp b/neo/tools/compilers/aas/BrushBSP.cpp
index 689b860f..7fb5e947 100644
--- a/neo/tools/compilers/aas/BrushBSP.cpp
+++ b/neo/tools/compilers/aas/BrushBSP.cpp
@@ -2258,7 +2258,8 @@ bool idBrushBSP::TryMergeLeafNodes( idBrushBSPPortal* portal, int side )
 	// replace every reference to node2 by a reference to node1
 	UpdateTreeAfterMerge_r( root, bounds, node2, node1 );
 
-	delete node2;
+	if (node2->GetFlags() & NODE_DONE)
+		delete node2;
 
 	return true;
 }