diff --git a/cura/CuraApplication.py b/cura/CuraApplication.py
index d7e0f1d374..43c11c26f0 100644
--- a/cura/CuraApplication.py
+++ b/cura/CuraApplication.py
@@ -817,7 +817,7 @@ class CuraApplication(QtApplication):
 
         # Compute the center of the objects when their origins are aligned.
         object_centers = [node.getMeshData().getCenterPosition().scale(node.getScale()) for node in group_node.getChildren() if node.getMeshData()]
-        if object_centers:
+        if object_centers and len(object_centers) > 0:
             middle_x = sum([v.x for v in object_centers]) / len(object_centers)
             middle_y = sum([v.y for v in object_centers]) / len(object_centers)
             middle_z = sum([v.z for v in object_centers]) / len(object_centers)