diff --git a/pycde-build/Dockerfile b/pycde-build/Dockerfile
index 0c06c35..869e5e5 100644
--- a/pycde-build/Dockerfile
+++ b/pycde-build/Dockerfile
@@ -1,5 +1,5 @@
 FROM quay.io/pypa/manylinux2014_x86_64
 
-RUN yum install -y wget
+RUN yum install -y wget ninja-build
 COPY get-capnp.sh /tmp
 RUN cd /tmp && bash get-capnp.sh