--- a/test/sieve.lua
+++ b/test/sieve.lua
@@ -14,7 +14,7 @@
     while 1 do
       local n = g()
       if n == nil then return end
-      if math.mod(n, p) ~= 0 then coroutine.yield(n) end
+      if math.fmod(n, p) ~= 0 then coroutine.yield(n) end
     end
   end)
 end