diff --git a/Dockerfile b/Dockerfile
index 6043b22732..4d9a01ae8a 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -92,9 +92,10 @@ COPY --from=builder    /build/target/release/buzz-admin /usr/local/bin/buzz-admi
 COPY --from=builder    /build/target/release/buzz-pair-relay /usr/local/bin/buzz-pair-relay
 COPY --from=web-builder /build/web/dist                 /srv/buzz/web
 
-ENV BUZZ_WEB_DIR=/srv/buzz/web
+# The web UI is bundled but disabled by default. Set
+# BUZZ_WEB_DIR=/srv/buzz/web to opt in.
 
-# 3000: app (WS + REST + web UI)  ·  8080: /_liveness, /_readiness  ·  9102: /metrics
+# 3000: app (WS + REST)  ·  8080: /_liveness, /_readiness  ·  9102: /metrics
 EXPOSE 3000 8080 9102
 
 USER buzz:buzz
diff --git a/TESTING.md b/TESTING.md
index a1ddb35ecd..a40bb5e306 100644
--- a/TESTING.md
+++ b/TESTING.md
@@ -272,6 +272,7 @@ out of the box with `just setup` or `just relay`. Common overrides:
 | `BUZZ_AUTO_MIGRATE`             | `false`                     | Opt in with `true`/`1`/`yes`/`on` to run embedded SQLx migrations on relay startup |
 | `RELAY_OWNER_PUBKEY`              | unset                       | Bootstrapped as `owner` in `relay_members` at first start |
 | `BUZZ_ALLOW_NIP_OA_AUTH`        | `false`                     | Enable NIP-OA owner attestation for membership |
+| `BUZZ_WEB_DIR`                  | unset                       | Set to the bundled `/srv/buzz/web` in the container to opt in to the browser web UI |
 
 CLI-side, only two matter for testing: