diff --git a/crates/ruff/src/commands/server.rs b/crates/ruff/src/commands/server.rs
index ef7b8a42e9f33..d35b2c1ce46f6 100644
--- a/crates/ruff/src/commands/server.rs
+++ b/crates/ruff/src/commands/server.rs
@@ -4,7 +4,12 @@ use crate::ExitStatus;
 use anyhow::Result;
 use ruff_server::Server;
 
-pub(crate) fn run_server(_preview: bool, worker_threads: NonZeroUsize) -> Result<ExitStatus> {
+pub(crate) fn run_server(preview: bool, worker_threads: NonZeroUsize) -> Result<ExitStatus> {
+    if !preview {
+        tracing::error!("--preview needs to be provided as a command line argument while the server is still unstable.\nFor example: `ruff server --preview`");
+        return Ok(ExitStatus::Error);
+    }
+
     let server = Server::new(worker_threads)?;
 
     server.run().map(|()| ExitStatus::Success)