diff --git a/Dockerfile b/Dockerfile
index 02a9ade..2ea9040 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,11 +1,21 @@
-FROM ubuntu:18.04
+FROM ubuntu:20.04
 
 # Maintainer of the docker image, not the code!
 MAINTAINER "Ian Hinder <ian.hinder@manchester.ac.uk>"
 
+ARG DEBIAN_FRONTEND=noninteractive
+
 RUN apt-get update -y && \
-    apt-get install -y python3 python3-pip python3-requests graphviz libgraphviz-dev curl && \
+    apt-get install -y \
+    python3 \
+    python3-pip \
+    python3-requests \
+    pkg-config \
+    graphviz \
+    libgraphviz-dev \
+    curl && \
     rm -rf /var/lib/apt/lists/*
+# Note: the ordering of these packages matters as libgraphviz-dev requires python3-pip
 
 COPY ./requirements.txt /app/requirements.txt
 
diff --git a/requirements.txt b/requirements.txt
index a787a1c..13e4558 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,11 +1,12 @@
-Click==7.0
-Flask==1.0.2
-itsdangerous==1.1.0
-Jinja2==2.10.1
+Click==8.1.3
+Flask==2.3.3
+itsdangerous==2.1.2
+Jinja2==3.1.4
 lxml==4.9.1
-MarkupSafe==1.1.1
+MarkupSafe==2.1.1
 natsort==6.0.0
 pygraphviz==1.5
 pyparsing==2.4.0
-urllib3==1.26.5
-Werkzeug==0.16.0
+pytest==7.4.2
+urllib3==1.26.19
+Werkzeug==3.0.3