diff --git a/codex-rs/exec-server-protocol/src/protocol.rs b/codex-rs/exec-server-protocol/src/protocol.rs
index 5c1f978d78..411a32f46d 100644
--- a/codex-rs/exec-server-protocol/src/protocol.rs
+++ b/codex-rs/exec-server-protocol/src/protocol.rs
@@ -186,7 +186,7 @@ impl EnvironmentInfo {
                 capability_discovery_sandbox: true,
                 environment_config_read: true,
                 sandboxed_file_streaming: true,
-                shell_snapshot_v2: cfg!(unix),
+                shell_snapshot_v2: false,
             },
         }
     }