diff --git a/ChangeLog b/ChangeLog
index 3d0c7e8ba..a3e0aeb88 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -6,6 +6,19 @@ Security
    * Wipe sensitive buffers on the stack in the CTR_DRBG and HMAC_DRBG
      modules.
 
+API Changes
+   * The following functions in the random generator modules have been
+     deprecated and replaced as shown below. The new functions change
+     the return type from void to int to allow returning error codes when
+     using MBEDTLS_<MODULE>_ALT for the underlying AES or message digest
+     primitive. Fixes #1798.
+     mbedtls_ctr_drbg_update() -> mbedtls_ctr_drbg_update_ret()
+     mbedtls_hmac_drbg_update() -> mbedtls_hmac_drbg_update_ret()
+
+New deprecations
+   * Deprecate mbedtls_ctr_drbg_update and mbedtls_hmac_drbg_update
+     in favor of functions that can return an error code.
+
 = mbed TLS 2.14.0 branch released 2018-11-19
 
 Security