diff --git a/.dockerignore b/.dockerignore
new file mode 100644
index 0000000..e53c6ed
--- /dev/null
+++ b/.dockerignore
@@ -0,0 +1,10 @@
+__pycache__/
+*.py[cod]
+*.pyo
+*.pyd
+*.swp
+*.tmp
+*.bak
+.git
+.gitignore
+.DS_Store
diff --git a/Dockerfile b/Dockerfile
index 3411f6c..02d26ba 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,22 +1,16 @@
 FROM python:3.11-slim
 
-RUN apt-get update && apt-get install -y --no-install-recommends \
-    libexpat1 \
-    && rm -rf /var/lib/apt/lists/*
+ENV PYTHONUNBUFFERED=1 \
+    THREEDTREES_METADATA_REFERENCE_DIR=/reference-data
 
-RUN mkdir -p /in /out /src /reference-data && chmod 777 /in /out /src /reference-data
-
-RUN pip install --no-cache-dir \
-    fiona \
-    pyproj \
-    shapely
+WORKDIR /src
 
+COPY requirements.txt ./
 COPY src/ /src/
 COPY reference-data/ /reference-data/
-RUN chmod -R a+rX /src
-RUN chmod -R a+rX /reference-data
 
-ENV THREEDTREES_METADATA_REFERENCE_DIR=/reference-data
+RUN pip install --no-cache-dir -r requirements.txt && \
+    chmod -R a+rX /src /reference-data
 
-WORKDIR /src
-CMD ["python", "run.py", "--help"]
+ENTRYPOINT ["python", "run.py"]
+CMD ["--help"]
diff --git a/requirements.txt b/requirements.txt
new file mode 100644
index 0000000..b05518e
--- /dev/null
+++ b/requirements.txt
@@ -0,0 +1,3 @@
+fiona==1.10.1
+pyproj==3.7.2
+shapely==2.1.2