diff --git a/xkb/xkb.c b/xkb/xkb.c
index 80e63e290..92729d651 100644
--- a/xkb/xkb.c
+++ b/xkb/xkb.c
@@ -5604,7 +5604,7 @@ _CheckSetGeom(XkbGeometryPtr geom, xkbSetGeometryReq * req, ClientPtr client)
     }
 
     for (i = 0; i < req->nKeyAliases; i++) {
-        if (!_XkbCheckRequestBounds(client, req, wire, wire + XkbKeyNameLength))
+        if (!_XkbCheckRequestBounds(client, req, wire, wire + 2 * XkbKeyNameLength))
                 return BadLength;
 
         if (XkbAddGeomKeyAlias(geom, &wire[XkbKeyNameLength], wire) == NULL)