diff --git a/docker-compose.yaml b/docker-compose.yaml
index b14559c..34b5b80 100644
--- a/docker-compose.yaml
+++ b/docker-compose.yaml
@@ -6,10 +6,13 @@ services:
       - POSTGRES_DB=${POSTGRES_DB}
       - POSTGRES_USER=${POSTGRES_USER}
       - POSTGRES_PASSWORD=${POSTGRES_PASSWORD}
+      # HA image's PGDATA is /home/postgres/pgdata/data, not /var/lib/postgresql/data.
+      # Mount the named volume there so data survives container rebuilds.
+      - PGDATA=/home/postgres/pgdata/data
     ports:
       - "5433:5432"
     volumes:
-      - timescale-data:/var/lib/postgresql/data
+      - timescale-data:/home/postgres/pgdata
     healthcheck:
       test: ["CMD-SHELL", "pg_isready -U ${POSTGRES_USER} -d ${POSTGRES_DB}"]
       interval: 10s