diff --git a/test/volume_server/README.md b/test/volume_server/README.md
index 774912329f..f422e32d16 100644
--- a/test/volume_server/README.md
+++ b/test/volume_server/README.md
@@ -15,10 +15,9 @@ If a `weed` binary is not found, the harness will build one automatically.
 ## Optional environment variables
 
 - `WEED_BINARY`: explicit path to the `weed` executable (disables auto-build).
-- `VOLUME_SERVER_IMPL`: select volume-server implementation (`go` default, `rust` for Rust launcher mode).
-- `VOLUME_SERVER_BINARY`: explicit path to the volume-server executable (overrides `VOLUME_SERVER_IMPL`).
-- `VOLUME_SERVER_RUST_MODE`: Rust launcher mode (`native` default, `exec` for direct Go delegation, `proxy` for Rust front proxy + Go backend).
-- `VOLUME_SERVER_RUST_REBUILD=1`: force rebuild of Rust volume-server binary in Rust mode.
+- `VOLUME_SERVER_IMPL`: select volume-server implementation (`go` default, `rust` for a Rust volume server).
+- `RUST_VOLUME_BINARY`: explicit path to the Rust volume-server executable (overrides crate auto-detect).
+- `VOLUME_SERVER_RUST_MODE`: `weed-volume-rs` launcher mode (`native` default, `exec` for direct Go delegation, `proxy` for Rust front proxy + Go backend).
 - `VOLUME_SERVER_IT_KEEP_LOGS=1`: keep temporary test directories and process logs.
 
 ## Current scope (Phase 0)