diff --git a/wireguard-control/src/backends/userspace.rs b/wireguard-control/src/backends/userspace.rs
index 2a8a648..961ae23 100644
--- a/wireguard-control/src/backends/userspace.rs
+++ b/wireguard-control/src/backends/userspace.rs
@@ -278,7 +278,7 @@ fn start_userspace_wireguard(iface: &InterfaceName) -> io::Result<Output> {
         command.args(&[iface.to_string()]).output()?
     } else {
         command
-            .env("WG_TUN_NAME_FILE", &format!("{VAR_RUN_PATH}/{iface}.name"))
+            .env("WG_TUN_NAME_FILE", format!("{VAR_RUN_PATH}/{iface}.name"))
             .args(["utun"])
             .output()?
     };