diff --git a/skimage/graph/_ncut.py b/skimage/graph/_ncut.py
index fbefca27..46ffb528 100644
--- a/skimage/graph/_ncut.py
+++ b/skimage/graph/_ncut.py
@@ -1,4 +1,8 @@
-import networkx as nx
+try:
+    import networkx as nx
+except ImportError:
+    import warnings
+    warnings.warn('RAGs require networkx')
 import numpy as np
 from scipy import sparse
 from . import _ncut_cy
diff --git a/skimage/graph/graph_cut.py b/skimage/graph/graph_cut.py
index 65d14585..e44f8a5c 100644
--- a/skimage/graph/graph_cut.py
+++ b/skimage/graph/graph_cut.py
@@ -2,7 +2,7 @@ try:
     import networkx as nx
 except ImportError:
     import warnings
-    warnings.warn('"cut_threshold" requires networkx')
+    warnings.warn('RAGs require networkx')
 import numpy as np
 from . import _ncut
 from . import _ncut_cy