diff -up src/sage/graphs/graph_generators.py.orig src/sage/graphs/graph_generators.py
--- src/sage/graphs/graph_generators.py.orig	2018-05-05 16:21:24.000000000 -0600
+++ src/sage/graphs/graph_generators.py	2018-05-16 13:35:59.299778933 -0600
@@ -886,7 +886,7 @@ class GraphGenerators():
             >A geng -d0D3 n=4 e=0-6
         """
         import subprocess
-        sp = subprocess.Popen("geng {0}".format(options), shell=True,
+        sp = subprocess.Popen("nauty-geng {0}".format(options), shell=True,
                               stdin=subprocess.PIPE, stdout=subprocess.PIPE,
                               stderr=subprocess.PIPE, close_fds=True)
         if debug: