Index: generic/xotcl.c
===================================================================
diff -u -rf4b1378f3136bc998645f230af38847bcf76d96b -r2b87beee1ba747adb0b2bf5e3379f80a3261ce63
--- generic/xotcl.c	(.../xotcl.c)	(revision f4b1378f3136bc998645f230af38847bcf76d96b)
+++ generic/xotcl.c	(.../xotcl.c)	(revision 2b87beee1ba747adb0b2bf5e3379f80a3261ce63)
@@ -8957,7 +8957,7 @@
   XOTclObject *obj = (XOTclObject*)cd;
 
   if (!obj) return XOTclObjErrType(interp, objv[0], "Object");
-  if (objc > 3)  XOTclObjErrArgCnt(interp, obj->cmdName, "set var ?value?");
+  if (objc > 3 || objc < 2) return XOTclObjErrArgCnt(interp, obj->cmdName, "set var ?value?");
   return setInstVar(interp, obj, objv[1], objc == 3 ? objv[2] : NULL);
 }