diff --git a/var/spack/repos/builtin/packages/py-yt/package.py b/var/spack/repos/builtin/packages/py-yt/package.py
index cf359121916..d56280e9f63 100644
--- a/var/spack/repos/builtin/packages/py-yt/package.py
+++ b/var/spack/repos/builtin/packages/py-yt/package.py
@@ -65,6 +65,7 @@ class PyYt(Package):
     depends_on("py-scipy", type=('build', 'run'), when="+scipy")
     depends_on("py-setuptools", type="build")
     depends_on("py-sympy", type=('build', 'run'))
+    depends_on("py-pillow", type=('build', 'run'))
     depends_on("python @2.7:2.999,3.4:")
 
     def install(self, spec, prefix):