diff --git a/skimage/graph/graph_cut.py b/skimage/graph/graph_cut.py
index 443b1561..d9fcfdef 100644
--- a/skimage/graph/graph_cut.py
+++ b/skimage/graph/graph_cut.py
@@ -3,7 +3,6 @@ try:
 except ImportError:
     import warnings
     warnings.warn('"cut_threshold" requires networkx')
-    nx = None
 import numpy as np