diff --git a/src/secp256k1/src/ecmult_const.h b/src/secp256k1/src/ecmult_const.h
index d4804b8b68..03bb33257d 100644
--- a/src/secp256k1/src/ecmult_const.h
+++ b/src/secp256k1/src/ecmult_const.h
@@ -1,17 +1,20 @@
 /**********************************************************************
  * Copyright (c) 2015 Andrew Poelstra                                 *
  * Distributed under the MIT software license, see the accompanying   *
  * file COPYING or http://www.opensource.org/licenses/mit-license.php.*
  **********************************************************************/
 
 #ifndef SECP256K1_ECMULT_CONST_H
 #define SECP256K1_ECMULT_CONST_H
 
 #include "scalar.h"
 #include "group.h"
 
-/* Here `bits` should be set to the maximum bitlength of the _absolute value_ of `q`, plus
- * one because we internally sometimes add 2 to the number during the WNAF conversion. */
+/**
+ * Multiply: R = q*A (in constant-time)
+ * Here `bits` should be set to the maximum bitlength of the _absolute value_ of `q`, plus
+ * one because we internally sometimes add 2 to the number during the WNAF conversion.
+ */
 static void secp256k1_ecmult_const(secp256k1_gej *r, const secp256k1_ge *a, const secp256k1_scalar *q, int bits);
 
 #endif /* SECP256K1_ECMULT_CONST_H */