diff --git a/codex-rs/core/src/guardian/approval_request.rs b/codex-rs/core/src/guardian/approval_request.rs
index 250ed7e9249..b89d020ca8d 100644
--- a/codex-rs/core/src/guardian/approval_request.rs
+++ b/codex-rs/core/src/guardian/approval_request.rs
@@ -160,6 +160,7 @@ fn command_assessment_action(
     }
 }
 
+#[cfg(unix)]
 fn guardian_command_source_tool_name(source: GuardianCommandSource) -> &'static str {
     match source {
         GuardianCommandSource::Shell => "shell",