diff --git a/src/TinyGsmClientSequansMonarch.h b/src/TinyGsmClientSequansMonarch.h
index 480ab16..935b38b 100644
--- a/src/TinyGsmClientSequansMonarch.h
+++ b/src/TinyGsmClientSequansMonarch.h
@@ -351,7 +351,7 @@ public:
   }
 
   bool poweroff() {
-    sendAT(GF("+SQNSSHDN=?"));
+    sendAT(GF("+SQNSSHDN"));
     return waitResponse();
   }