diff --git a/skimage/graph/tests/test_rag.py b/skimage/graph/tests/test_rag.py
index 0d5fa2ab..4e287ceb 100644
--- a/skimage/graph/tests/test_rag.py
+++ b/skimage/graph/tests/test_rag.py
@@ -100,6 +100,7 @@ def test_cut_normalized():
     assert new_labels.max() == 1
 
 
+@skipif(not is_installed('networkx'))
 def test_rag_error():
     img = np.zeros((10, 10, 3), dtype='uint8')
     labels = np.zeros((10, 10), dtype='uint8')