diff --git a/Dockerfile.moth-devel b/Dockerfile.moth-devel
index fef3b43..35a980f 100644
--- a/Dockerfile.moth-devel
+++ b/Dockerfile.moth-devel
@@ -6,7 +6,10 @@ RUN apk --no-cache add \
       jpeg-dev \
       zlib-dev \
     && \
-    pip3 install pillow
+    pip3 install \
+      scapy==2.4.2 \
+      pillow==5.4.1
+
 
 COPY devel /app/
 COPY example-puzzles /puzzles/
diff --git a/README.md b/README.md
index f47399c..58f5d7d 100644
--- a/README.md
+++ b/README.md
@@ -27,6 +27,8 @@ Running a Development Server
 
 And point a browser to http://localhost:8080/ (or whatever host is running the server).
 
+The development server includes a number of Python libraries that we have found useful in writing puzzles.
+
 When you're ready to create your own puzzles,
 read [the devel server documentation](docs/devel-server.md).