diff --git a/src/system/its.1648 b/src/system/its.1648
index 846fd131..680eebbe 100644
--- a/src/system/its.1648
+++ b/src/system/its.1648
@@ -11949,7 +11949,7 @@ IFN TTLPTP,	DV LPT,LPTO,%DVOUT
 		DV DIRHNG,DIRHO,%DVIN
 		DV TRAP,TRPDEV,%DVIN+%DVOUT+%DVDIR+%DVDEL+%DVLNK
 		DV LOCK,LCKO,%DVOUT
-		DV UBI,UBIO,%DVIN
+IFN KS10P,	DV UBI,UBIO,%DVIN
 		DV TTY,TTYO1,%DVIN+%DVOUT+%DVDIR
 		DV NUL,NULO,%DVIN+%DVOUT
 		DV USR,USRO,%DVIN+%DVOUT