diff --git a/codex-rs/core/src/shell.rs b/codex-rs/core/src/shell.rs
index 0da18bd15f..e44957555c 100644
--- a/codex-rs/core/src/shell.rs
+++ b/codex-rs/core/src/shell.rs
@@ -336,7 +336,7 @@ mod snapshots {
         let zshrc = home.join(".zshrc");
 
         capture_script.push_str(
-            &format!("source {}; setopt posixbuiltins; export -p; {{ alias | sed 's/^/alias /'; }} 2>/dev/null || true", zshrc.display()),
+            &format!(". {}; setopt posixbuiltins; export -p; {{ alias | sed 's/^/alias /'; }} 2>/dev/null || true", zshrc.display()),
         );
         let output = tokio::process::Command::new(shell_path)
             .arg("-lc")