1 files changed, 13 insertions, 3 deletions
diff --git a/macros/luatex/generic/lualibs/lualibs-math.lua b/macros/luatex/generic/lualibs/lualibs-math.lua
index e5668a5db0..6105bc3c2d 100644
--- a/macros/luatex/generic/lualibs/lualibs-math.lua
+++ b/macros/luatex/generic/lualibs/lualibs-math.lua
@@ -14,9 +14,19 @@ end
 
 if not math.round then
 
-    local floor = math.floor
+    if xmath then
+
+        math.round = xmath.round
+
+    else
 
-    function math.round(x) return floor(x + 0.5) end
+        local floor = math.floor
+
+        function math.round(x)
+            return x < 0 and -floor(-x + 0.5) or floor(x + 0.5)
+        end
+
+    end
 
 end
 
@@ -141,7 +151,7 @@ if not math.ult then
 
     local floor = math.floor
 
-    function math.tointeger(m,n)
+    function math.ult(m,n)
         -- not ok but i'm not motivated to look into it now
         return floor(m) < floor(n) -- unsigned comparison needed
     end