diff --git a/examples/postgres.py b/examples/postgres.py
index de61b65c..534b5484 100644
--- a/examples/postgres.py
+++ b/examples/postgres.py
@@ -19,7 +19,7 @@
 # the backend uses psycopg2 under the hood, so any valid connection string for it will
 # work; just replace the scheme with `shillelagh+multicorn2`
 engine = create_engine(
-    "shillelagh+multicorn2://shillelagh:shillelagh123@localhost:12345/shillelagh",
+    "shillelagh+multicorn2://shillelagh:shillelagh123@localhost:5432/shillelagh",
 )
 connection = engine.connect()
 
diff --git a/postgres/Dockerfile b/postgres/Dockerfile
index 5d45189b..267c7786 100644
--- a/postgres/Dockerfile
+++ b/postgres/Dockerfile
@@ -10,10 +10,12 @@ USER root
 # Install system dependencies
 RUN apt-get update && apt-get install -y \
     build-essential \
+    git \
     postgresql-server-dev-13 \
     python3 \
     python3-dev \
     python3-pip \
+    python3-venv \
     wget
 
 # Download, build, and install multicorn2
@@ -24,7 +26,13 @@ RUN wget https://github.com/pgsql-io/multicorn2/archive/refs/tags/v2.5.tar.gz &&
     make install
 
 
-RUN pip install -e '.[all]'
+# Create a virtual environment and install dependencies
+RUN python3 -m venv /code/venv && \
+    /code/venv/bin/pip install --upgrade pip && \
+    /code/venv/bin/pip install -e '.[all]'
+
+# Set environment variable for PostgreSQL to use the virtual environment
+ENV PATH="/code/venv/bin:$PATH"
 
 # Switch back to the default postgres user
 USER postgres
diff --git a/postgres/docker-compose.yml b/postgres/docker-compose.yml
index 6b2e1e15..5d905388 100644
--- a/postgres/docker-compose.yml
+++ b/postgres/docker-compose.yml
@@ -2,7 +2,9 @@ version: '3.8'
 
 services:
   postgres:
-    build: .
+    build:
+      context: ..
+      dockerfile: postgres/Dockerfile
     environment:
       POSTGRES_PASSWORD: shillelagh123
       POSTGRES_USER: shillelagh
@@ -10,7 +12,6 @@ services:
     volumes:
       - db_data:/var/lib/postgresql/data
       - ./init.sql:/docker-entrypoint-initdb.d/init.sql:ro
-      - ..:/src
     ports:
       - "5432:5432"