diff --git a/Marlin/src/feature/runout.h b/Marlin/src/feature/runout.h
index 48470e6c26f43e0197cfac0f8b04dd464644d7c9..f937679055864de43afa84fcc339e5c602ff3901 100644
--- a/Marlin/src/feature/runout.h
+++ b/Marlin/src/feature/runout.h
@@ -101,7 +101,7 @@ class TFilamentMonitor : public FilamentMonitorBase {
             #if NUM_RUNOUT_SENSORS > 1
               host_action_filament_runout(false);
               SERIAL_CHAR(' ');
-              SERIAL_ECHO(int(active_extruder));
+              SERIAL_ECHOLN(int(active_extruder));
             #else
               host_action_filament_runout();
             #endif