diff --git a/codex-rs/core/src/default_client.rs b/codex-rs/core/src/default_client.rs
index 55707fad3d..8e4635460c 100644
--- a/codex-rs/core/src/default_client.rs
+++ b/codex-rs/core/src/default_client.rs
@@ -288,7 +288,7 @@ mod tests {
     #[test]
     fn test_get_codex_user_agent() {
         let user_agent = get_codex_user_agent();
-        assert!(user_agent.starts_with(&format!("{}/", originator().value)));
+        assert!(user_agent.starts_with("codex_cli_rs/"));
     }
 
     #[tokio::test]
@@ -329,10 +329,7 @@ mod tests {
         let originator_header = headers
             .get("originator")
             .expect("originator header missing");
-        assert_eq!(
-            originator_header.to_str().unwrap(),
-            originator().value.as_str()
-        );
+        assert_eq!(originator_header.to_str().unwrap(), "codex_cli_rs");
 
         // User-Agent matches the computed Codex UA for that originator
         let expected_ua = get_codex_user_agent();
@@ -368,11 +365,9 @@ mod tests {
     #[cfg(target_os = "macos")]
     fn test_macos() {
         use regex_lite::Regex;
-        let originator = originator().value.clone();
         let user_agent = get_codex_user_agent();
         let re = Regex::new(
-            format!(r"^{originator}/\d+\.\d+\.\d+ \(Mac OS \d+\.\d+\.\d+; (x86_64|arm64)\) (\S+)$")
-                .as_str(),
+            r"^codex_cli_rs/\d+\.\d+\.\d+ \(Mac OS \d+\.\d+\.\d+; (x86_64|arm64)\) (\S+)$",
         )
         .unwrap();
         assert!(re.is_match(&user_agent));