diff --git a/sys/kern/sys_generic.c b/sys/kern/sys_generic.c
index 9cbf7138b006..239292834012 100644
--- a/sys/kern/sys_generic.c
+++ b/sys/kern/sys_generic.c
@@ -652,18 +652,19 @@ int
 sys_ioctl(struct thread *td, struct ioctl_args *uap)
 {
 	u_char smalldata[SYS_IOCTL_SMALL_SIZE] __aligned(SYS_IOCTL_SMALL_ALIGN);
-	u_long com;
+	uint32_t com;
 	int arg, error;
 	u_int size;
 	caddr_t data;
 
+#ifdef INVARIANTS
 	if (uap->com > 0xffffffff) {
 		printf(
 		    "WARNING pid %d (%s): ioctl sign-extension ioctl %lx\n",
 		    td->td_proc->p_pid, td->td_name, uap->com);
-		uap->com &= 0xffffffff;
 	}
-	com = uap->com;
+#endif
+	com = (uint32_t)uap->com;
 
 	/*
 	 * Interpret high order word to find amount of data to be