diff --git a/cpukit/libnetworking/rtems/rtems_mii_ioctl.c b/cpukit/libnetworking/rtems/rtems_mii_ioctl.c
index f7c1818695..fc01f2bc30 100644
--- a/cpukit/libnetworking/rtems/rtems_mii_ioctl.c
+++ b/cpukit/libnetworking/rtems/rtems_mii_ioctl.c
@@ -57,7 +57,6 @@
 #include <inttypes.h>
 
 #undef _KERNEL
-#undef KERNEL
 
 #include <rtems/rtems_mii_ioctl.h>