diff --git a/examples/reverb-calculator.pd_lua b/examples/reverb-calculator.pd_lua
index 68712337f5f614549db7acf53a051d1c080f86ac..000d6f24fd6a2f13911a0ab1f2c17b48a0a245cf 100644
--- a/examples/reverb-calculator.pd_lua
+++ b/examples/reverb-calculator.pd_lua
@@ -11,7 +11,7 @@ function R:initialize(sel, atoms)
 end
 
 local gcd = function(m, n)
-  while m ~= 0 do m, n = math.mod(n, m), m end
+  while m ~= 0 do m, n = n % m, m end
   return n
 end