diff --git a/python/setup.py b/python/setup.py
index ac2363160..19fbdcd13 100644
--- a/python/setup.py
+++ b/python/setup.py
@@ -21,6 +21,7 @@ setuptools.setup(
         "h5py",                                                                                     # requires numpy
         "vtk",
         "matplotlib",                                                                               # requires numpy, pillow
+        "pyaml"
     ],
     classifiers = [
         "Intended Audience :: Science/Research",