diff --git a/include/mbedtls/bignum.h b/include/mbedtls/bignum.h
index 073b4a4..e938232 100644
--- a/include/mbedtls/bignum.h
+++ b/include/mbedtls/bignum.h
@@ -871,6 +871,37 @@
                      int (*f_rng)(void *, unsigned char *, size_t),
                      void *p_rng );
 
+/** Generate a random number uniformly in a range.
+ *
+ * This function generates a random number between \p min inclusive and
+ * \p N exclusive.
+ *
+ * The procedure complies with RFC 6979 §3.3 (deterministic ECDSA)
+ * when the RNG is a suitably parametrized instance of HMAC_DRBG
+ * and \p min is \c 1.
+ *
+ * \note           There are `N - min` possible outputs. The lower bound
+ *                 \p min can be reached, but the upper bound \p N cannot.
+ *
+ * \param X        The destination MPI. This must point to an initialized MPI.
+ * \param min      The minimum value to return.
+ *                 It must be nonnegative.
+ * \param N        The upper bound of the range, exclusive.
+ *                 In other words, this is one plus the maximum value to return.
+ *                 \p N must be strictly larger than \p min.
+ * \param f_rng    The RNG function to use. This must not be \c NULL.
+ * \param p_rng    The RNG parameter to be passed to \p f_rng.
+ *
+ * \return         \c 0 if successful.
+ * \return         #MBEDTLS_ERR_MPI_ALLOC_FAILED if a memory allocation failed.
+ * \return         Another negative error code on failure.
+ */
+int mbedtls_mpi_random( mbedtls_mpi *X,
+                        mbedtls_mpi_sint min,
+                        const mbedtls_mpi *N,
+                        int (*f_rng)(void *, unsigned char *, size_t),
+                        void *p_rng );
+
 /**
  * \brief          Compute the greatest common divisor: G = gcd(A, B)
  *