diff --git a/Dockerfile b/Dockerfile
index 8f296df..aa4f3cc 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -4,9 +4,12 @@ FROM python:3.12-slim
 WORKDIR /app
 
 # Install system dependencies (libpq for psycopg2)
+# git is required at build time: both risk-engine and requirements.txt install
+# shared libraries from git+https URLs, and pip shells out to git to do it.
 RUN apt-get update && apt-get install -y --no-install-recommends \
     build-essential \
     libpq-dev \
+    git \
     && rm -rf /var/lib/apt/lists/*
 
 # Create non-root user