diff --git a/Design:-Runnable-Project.md b/Design:-Runnable-Project.md
index a97251d..45f35e5 100644
--- a/Design:-Runnable-Project.md
+++ b/Design:-Runnable-Project.md
@@ -45,8 +45,9 @@ We should also have an example Dockerfile that can be used to build and run a pr
 
 FROM resin/%%RESIN_MACHINE_NAME%%-node:8-slim
 
+# Uncomment the next three lines if you want GPIO for Pi
 #RUN apt-get update && apt-get install -yq \
-#    build-essential && \
+#    rpi.gpio && \
 #    apt-get clean && rm -rf /var/lib/apt/lists/*
 
 WORKDIR /usr/src/app
@@ -69,4 +70,5 @@ A really minimal Dockerfile to build an image (but not run) could be as simple a
 
 ```FROM node:8-onbuild
 VOLUME /root/.node-red
-EXPOSE 1880```
\ No newline at end of file
+EXPOSE 1880
+```
\ No newline at end of file