diff --git a/setup.py b/setup.py
index cd5fbeae..46185f90 100644
--- a/setup.py
+++ b/setup.py
@@ -19,5 +19,5 @@
     #test_suite = "smop.testsuite.test_lexer",
     #include_package_data = True,
     #package_data = { 'smop': ['*.m', 'Makefile'], },
-    install_requires = ['ply', 'numpy', 'scipy', 'networkx', 'pygraphviz'],
+    install_requires = ['ply', 'numpy', 'scipy', 'networkx'],
 )