diff --git a/bip-schnorr/reference.py b/bip-schnorr/reference.py
index 4ac93eea..79be6903 100644
--- a/bip-schnorr/reference.py
+++ b/bip-schnorr/reference.py
@@ -4,7 +4,7 @@ import binascii
 p = 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEFFFFFC2F
 n = 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141
 
-# Points are tuples X and Y coordinates and the point at infinity is
+# Points are tuples of X and Y coordinates and the point at infinity is
 # represented by the None keyword.
 G = (0x79BE667EF9DCBBAC55A06295CE870B07029BFCDB2DCE28D959F2815B16F81798, 0x483ADA7726A3C4655DA4FBFC0E1108A8FD17B448A68554199C47D08FFB10D4B8)