diff --git a/include/polarssl/ctr_drbg.h b/include/polarssl/ctr_drbg.h
index 8b0f38a159..3b2b27c08e 100644
--- a/include/polarssl/ctr_drbg.h
+++ b/include/polarssl/ctr_drbg.h
@@ -204,7 +204,8 @@ int ctr_drbg_random( void *p_rng,
  * \param ctx           CTR_DRBG context
  * \param path          Name of the file
  *
- * \return              0 if successful, 1 on file error, or
+ * \return              0 if successful,
+ *                      POLARSSL_ERR_CTR_DRBG_FILE_IO_ERROR on file error, or
  *                      POLARSSL_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED
  */
 int ctr_drbg_write_seed_file( ctr_drbg_context *ctx, const char *path );
@@ -216,7 +217,8 @@ int ctr_drbg_write_seed_file( ctr_drbg_context *ctx, const char *path );
  * \param ctx           CTR_DRBG context
  * \param path          Name of the file
  *
- * \return              0 if successful, 1 on file error,
+ * \return              0 if successful,
+ *                      POLARSSL_ERR_CTR_DRBG_FILE_IO_ERROR on file error,
  *                      POLARSSL_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED or
  *                      POLARSSL_ERR_CTR_DRBG_INPUT_TOO_BIG
  */