diff --git a/Dockerfile b/Dockerfile
index 94c0ba5..23ccecb 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,6 +1,9 @@
 FROM python:3.6
 LABEL maintainer="dan.leehr@duke.edu"
 
+# cwltool requires nodejs
+RUN apt-get update && apt-get install -y nodejs
+
 RUN mkdir -p /app
 COPY . /app
 RUN pip install /app