diff --git a/greatest_common_divisor.lua b/greatest_common_divisor.lua
index 9d475cc..bc6dd16 100644
--- a/greatest_common_divisor.lua
+++ b/greatest_common_divisor.lua
@@ -1,6 +1,8 @@
--- The greatest common divisor (GCD) of two numbers X and Y is, as the
--- name suggests, the largest number which evenly divides both X and
--- Y.  Implement the function below to calculate this.
+-- The greatest common divisor (GCD) of two numbers is, as the name
+-- suggests, the largest number which evenly divides both.  Implement
+-- the function below to calculate this.  It's recommended that you
+-- use Euclid's algorithm but feel free to use another approach if you
+-- want.
 --
 -- Solution --------------------------------------------------------------------
 function greatest_common_divisor(x, y)