diff --git a/include/mbedtls/bignum.h b/include/mbedtls/bignum.h
index ee37430..9d15955 100644
--- a/include/mbedtls/bignum.h
+++ b/include/mbedtls/bignum.h
@@ -758,11 +758,11 @@
  *
  * \param Q        The destination MPI for the quotient.
  *                 This may be \c NULL if the value of the
- *                 quotient is not needed.
+ *                 quotient is not needed. This must not alias A or B.
  * \param R        The destination MPI for the remainder value.
  *                 This may be \c NULL if the value of the
- *                 remainder is not needed.
- * \param A        The dividend. This must point to an initialized MPi.
+ *                 remainder is not needed. This must not alias A or B.
+ * \param A        The dividend. This must point to an initialized MPI.
  * \param B        The divisor. This must point to an initialized MPI.
  *
  * \return         \c 0 if successful.
@@ -779,10 +779,10 @@
  *
  * \param Q        The destination MPI for the quotient.
  *                 This may be \c NULL if the value of the
- *                 quotient is not needed.
+ *                 quotient is not needed.  This must not alias A.
  * \param R        The destination MPI for the remainder value.
  *                 This may be \c NULL if the value of the
- *                 remainder is not needed.
+ *                 remainder is not needed.  This must not alias A.
  * \param A        The dividend. This must point to an initialized MPi.
  * \param b        The divisor.
  *
@@ -837,6 +837,7 @@
  * \brief          Perform a sliding-window exponentiation: X = A^E mod N
  *
  * \param X        The destination MPI. This must point to an initialized MPI.
+ *                 This must not alias E or N.
  * \param A        The base of the exponentiation.
  *                 This must point to an initialized MPI.
  * \param E        The exponent MPI. This must point to an initialized MPI.