diff --git a/README.md b/README.md
index 2e24fc9..b7bfd6b 100644
--- a/README.md
+++ b/README.md
@@ -103,7 +103,7 @@ export default defineConfig({
     version: "18.0",                  // required — image tag, and part of the DB template cache key
     serviceName: "odoo",              // default — compose service to exec/log against
     databaseServiceName: "db",        // default
-    postgresImage: "postgres:16",     // default
+    postgresImage: "postgres:16",     // default; postgres:18 images work too
     build: {                          // default: none — the CLI GENERATES a Dockerfile from this
       aptPackages: ["tesseract-ocr"], //   (FROM odoo:<version>, apt layer, pip layer, then COPYs)
       pipRequirements: ["backend/requirements.txt"],
diff --git a/package.json b/package.json
index a85ed63..a916711 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@basaltbytes/odoo-agentic-dev",
-  "version": "0.1.0-beta.20",
+  "version": "0.1.0-beta.21",
   "description": "Agent-friendly local Odoo development runtime: worktree-isolated databases, ports, and Docker Compose stacks",
   "keywords": [
     "agentic",
diff --git a/src/core/compose-model.ts b/src/core/compose-model.ts
index dc874f5..6df03fe 100644
--- a/src/core/compose-model.ts
+++ b/src/core/compose-model.ts
@@ -10,6 +10,8 @@ export type ComposeModel = {
 };
 
 export const GENERATED_COMPOSE_RELATIVE_PATH = ".odoo-agentic-dev/compose.generated.yml";
+export const POSTGRES_DATA_MOUNT = "/var/lib/postgresql/data";
+export const POSTGRES_DATA_DIR = `${POSTGRES_DATA_MOUNT}/pgdata`;
 export const POSTGRES_HEALTHCHECK_COMMAND =
   'test "$(cat /proc/1/comm)" = postgres && pg_isready -U odoo -d postgres';
 
@@ -102,14 +104,22 @@ export const buildComposeModel = (
       [dbService]: {
         image: recipe.odoo.postgresImage,
         restart: "unless-stopped",
-        environment: { POSTGRES_USER: "odoo", POSTGRES_PASSWORD: "odoo", POSTGRES_DB: "postgres" },
+        environment: {
+          POSTGRES_USER: "odoo",
+          POSTGRES_PASSWORD: "odoo",
+          POSTGRES_DB: "postgres",
+          // postgres:18+ images refuse a volume mounted on their pre-18 default
+          // data directory (/var/lib/postgresql/data). An explicit PGDATA below the
+          // mount keeps one layout that every major from 13 to 18 accepts.
+          PGDATA: POSTGRES_DATA_DIR,
+        },
         healthcheck: {
           test: ["CMD-SHELL", POSTGRES_HEALTHCHECK_COMMAND],
           interval: "2s",
           timeout: "5s",
           retries: 30,
         },
-        volumes: ["db-data:/var/lib/postgresql/data"],
+        volumes: [`db-data:${POSTGRES_DATA_MOUNT}`],
         labels,
       },
       [odooService]: {
diff --git a/test/core/compose-model.test.ts b/test/core/compose-model.test.ts
index b758381..0a1862b 100644
--- a/test/core/compose-model.test.ts
+++ b/test/core/compose-model.test.ts
@@ -29,6 +29,14 @@ describe("buildComposeModel", () => {
     expect(parse(renderComposeYaml(model))).toEqual(JSON.parse(JSON.stringify(model)));
   });
 
+  it("keeps the database under an explicit PGDATA so postgres 13 to 18+ images all start", () => {
+    // postgres:18+ images abort when a volume sits on their pre-18 default data
+    // directory; an explicit PGDATA below the mount is accepted by every major.
+    const db = model.services["db"] as Record<string, any>;
+    expect(db["environment"]["PGDATA"]).toBe("/var/lib/postgresql/data/pgdata");
+    expect(db["volumes"]).toEqual(["db-data:/var/lib/postgresql/data"]);
+  });
+
   it("uses build+image when a dockerfile is configured", () => {
     const odoo = model.services["odoo"] as Record<string, unknown>;
     expect(odoo["build"]).toEqual({ context: ".", dockerfile: "Dockerfile.odoo" });