diff --git a/qtensor/optimisation/Optimizer.py b/qtensor/optimisation/Optimizer.py
index ccb9a37b..17be473a 100644
--- a/qtensor/optimisation/Optimizer.py
+++ b/qtensor/optimisation/Optimizer.py
@@ -282,8 +282,9 @@ def get_ordering_ints(self, graph, inplace=True):
         #print('graph nodes', len(graph.nodes))
         #print('pgraph nodes', len(p_graph.nodes))
         # Remove parallel vars from graph
-        for var in par_vars:
-            qtree.graph_model.base.remove_node(self.graph, var)
+        if hasattr(self, 'graph'):
+            for var in par_vars:
+                qtree.graph_model.base.remove_node(self.graph, var)
         #self.graph = p_graph
         return peo, [self.treewidth]