Index: codex-rs/arg0/src/lib.rs
--- codex-rs/arg0/src/lib.rs.orig
+++ codex-rs/arg0/src/lib.rs
@@ -118,6 +118,10 @@ where
     runtime.block_on(async move {
         let codex_linux_sandbox_exe: Option<PathBuf> = if cfg!(target_os = "linux") {
             std::env::current_exe().ok()
+        } else if cfg!(target_os = "openbsd") {
+            std::env::current_exe()
+                .ok()
+                .or(Some(PathBuf::from("${PREFIX}/bin/codex")))
         } else {
             None
         };
@@ -233,7 +237,8 @@ pub fn prepend_path_entry_for_codex_aliases() -> std::
         #[cfg(target_os = "linux")]
         LINUX_SANDBOX_ARG0,
     ] {
-        let exe = std::env::current_exe()?;
+        let exe = std::env::current_exe()
+            .unwrap_or_else(|_| PathBuf::from("${PREFIX}/bin/codex"));
 
         #[cfg(unix)]
         {
