diff --git a/Dockerfile.moth-devel b/Dockerfile.moth-devel
index 20c659a..6e8466a 100644
--- a/Dockerfile.moth-devel
+++ b/Dockerfile.moth-devel
@@ -16,6 +16,5 @@ COPY devel /app/
 COPY example-puzzles /puzzles/
 COPY theme /theme/
 
-WORKDIR /moth/
 ENTRYPOINT [ "python3", "/app/devel-server.py" ]
 CMD [ "--bind", "0.0.0.0:8080", "--puzzles", "/puzzles", "--theme", "/theme" ]
diff --git a/README.md b/README.md
index 58f5d7d..9d9d9c9 100644
--- a/README.md
+++ b/README.md
@@ -23,8 +23,14 @@ and comes with a JavaScript-based scoreboard to display team rankings.
 Running a Development Server
 ============================
 
+To use example puzzles
+
     docker run --rm -it -p 8080:8080 dirtbags/moth-devel
 
+or, to use your own puzzles
+
+    docker run --rm -it -p 8080:8080 -v /path/to/puzzles:/puzzles:ro dirtbags/moth-devel
+
 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.
diff --git a/devel/devel-server.py b/devel/devel-server.py
index 1a6167d..37fda8c 100755
--- a/devel/devel-server.py
+++ b/devel/devel-server.py
@@ -43,7 +43,11 @@ class MothRequestHandler(http.server.SimpleHTTPRequestHandler):
     
     def __init__(self, request, client_address, server):
         self.directory = str(server.args["theme_dir"])
-        super().__init__(request, client_address, server)
+        try:
+            super().__init__(request, client_address, server, directory=server.args["theme_dir"])
+        except TypeError:
+            super().__init__(request, client_address, server)
+
 
     # Backport from Python 3.7
     def translate_path(self, path):