diff --git a/internal/api/terminal.go b/internal/api/terminal.go
index 2d56ea6..90a5a12 100644
--- a/internal/api/terminal.go
+++ b/internal/api/terminal.go
@@ -105,6 +105,12 @@ func (s *Server) handleTerminalWS(w http.ResponseWriter, r *http.Request) {
 			}
 		}
 
+		// Ignore invalid shell paths (e.g., single characters from race condition)
+		if len(shell) <= 1 {
+			conn.WriteJSON(wsMessage{Type: "error", Data: "invalid shell config"})
+			return
+		}
+
 		if _, err := os.Stat(shell); err != nil {
 			conn.WriteJSON(wsMessage{Type: "error", Data: fmt.Sprintf("shell not found: %s", shell)})
 			return