diff --git a/Software/System/Linux/Modules/KernelDriver/Demo/Misc/demo_misc.c b/Software/System/Linux/Modules/KernelDriver/Demo/Misc/demo_misc.c
index d123dee..a0a58bc 100644
--- a/Software/System/Linux/Modules/KernelDriver/Demo/Misc/demo_misc.c
+++ b/Software/System/Linux/Modules/KernelDriver/Demo/Misc/demo_misc.c
@@ -84,7 +84,7 @@ static long demo_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
     }
         break;
     default:
-        break;
+        return -ENOIOCTLCMD;
     }
     return 0;
 }