diff --git a/crates/client/src/shell.rs b/crates/client/src/shell.rs
index 39addca..9593938 100644
--- a/crates/client/src/shell.rs
+++ b/crates/client/src/shell.rs
@@ -119,9 +119,13 @@ impl PersistentShell {
                     }
                     Ok(Ok(_)) => {
                         debug!("stdout line: {line:?}");
-                        if line.trim_end().starts_with(SENTINEL) {
-                            // Parse exit code from sentinel line
-                            let code_str = line.trim_end().trim_start_matches(SENTINEL);
+                        if line.contains(SENTINEL) {
+                            // Parse exit code from sentinel line (use contains for Windows
+                            // compatibility: cmd.exe echoes the prompt before the sentinel,
+                            // e.g. "C:\Users\...>__HELIOS_DONE__0\r\n")
+                            let sentinel_pos = line.find(SENTINEL).unwrap_or(0);
+                            let code_str = &line[sentinel_pos..];
+                            let code_str = code_str.trim_end().trim_start_matches(SENTINEL);
                             exit_code = code_str.trim().parse().unwrap_or(0);
                             break;
                         } else {