diff --git a/chals/crypto/diagonal/Dockerfile b/chals/crypto/diagonal/Dockerfile
index 4e00805..c4c0e3d 100644
--- a/chals/crypto/diagonal/Dockerfile
+++ b/chals/crypto/diagonal/Dockerfile
@@ -1,14 +1,14 @@
 FROM ubuntu:20.04
 
 RUN apt-get update && apt-get install -y socat python3
-
+RUN pip3 install numpy
 RUN adduser chal
 
 RUN mkdir -p /chal
 WORKDIR /chal
 
-COPY chal.py flag.txt ./
-RUN chmod 555 chal.py
+COPY server.py ./
+RUN chmod 555 server.py
 USER chal
 
-CMD socat -T60 TCP-LISTEN:1337,fork,reuseaddr EXEC:"python3 -u chal.py",stderr
+CMD socat -T60 TCP-LISTEN:1337,fork,reuseaddr EXEC:"python3 -u server.py",stderr