diff --git a/pygcn/utils.py b/pygcn/utils.py
index 9b53c5b..527ad2d 100644
--- a/pygcn/utils.py
+++ b/pygcn/utils.py
@@ -4,7 +4,7 @@
 
 
 def encode_onehot(labels):
-    classes = set(labels)
+    classes = sorted(set(labels))
     classes_dict = {c: np.identity(len(classes))[i, :] for i, c in
                     enumerate(classes)}
     labels_onehot = np.array(list(map(classes_dict.get, labels)),