diff --git a/crates/rpc/proto/zed.proto b/crates/rpc/proto/zed.proto
index 5ae127e2775af712895353d76e9a5c474f02b509..21fe81ca1b16cf32061ffa6b5e88593bf79fc25d 100644
--- a/crates/rpc/proto/zed.proto
+++ b/crates/rpc/proto/zed.proto
@@ -368,7 +368,7 @@ message JoinProject {
 }
 
 message JoinProjectResponse {
-    uint32 replica_id = 1;
+    optional uint32 replica_id = 1;
     repeated WorktreeMetadata worktrees = 2;
     repeated Collaborator collaborators = 3;
     repeated LanguageServer language_servers = 4;