diff --git a/src/helpers/SubsurfaceTree.cpp b/src/helpers/SubsurfaceTree.cpp
index 53174d91..dc30fc9c 100644
--- a/src/helpers/SubsurfaceTree.cpp
+++ b/src/helpers/SubsurfaceTree.cpp
@@ -3,6 +3,9 @@
 #include "../Compositor.hpp"
 
 void addSurfaceGlobalOffset(SSurfaceTreeNode* node, int* lx, int* ly) {
+    if (!node->pSurface)
+        return; // ? how does this happen sometimes
+
     *lx += node->pSurface->sx;
     *ly += node->pSurface->sy;