diff --git a/skimage/graph/rag.py b/skimage/graph/rag.py
index 4447c4e3..f3c22f83 100644
--- a/skimage/graph/rag.py
+++ b/skimage/graph/rag.py
@@ -314,7 +314,7 @@ def draw_rag(labels, rag, img, border_color=None, node_color='yellow',
         # Because we kept the offset as 1
         rag.node[region['label'] - 1]['centroid'] = region['centroid']
 
-    if not border_color is None:
+    if border_color is not None:
         border_color = cc.to_rgb(border_color)
         out = segmentation.mark_boundaries(out, rag_labels, color=border_color)