diff --git a/edwards25519/const.go b/edwards25519/const.go
index ea5b77a..288533d 100644
--- a/edwards25519/const.go
+++ b/edwards25519/const.go
@@ -4,10 +4,12 @@
 
 package edwards25519
 
+// d is 37095705934669439343138083508754565189542113879843219016388785533085940283555
 var d = FieldElement{
 	-10913610, 13857413, -15372611, 6949391, 114729, -8787816, -6275908, -3247719, -18696448, -12055116,
 }
 
+// d2 is 2*d: 16295367250680780974490674513165176452449235426866156013048779062215315747161
 var d2 = FieldElement{
 	-21827239, -5839606, -30745221, 13898782, 229458, 15978800, -12551817, -6495438, 29715968, 9444199,
 }