diff --git a/include/mbedtls/ccm.h b/include/mbedtls/ccm.h
index e1dc124..dfb1b5e 100644
--- a/include/mbedtls/ccm.h
+++ b/include/mbedtls/ccm.h
@@ -53,6 +53,8 @@
 
 #define MBEDTLS_ERR_CCM_BAD_INPUT       -0x000D /**< Bad input parameters to the function. */
 #define MBEDTLS_ERR_CCM_AUTH_FAILED     -0x000F /**< Authenticated decryption failed. */
+
+/* MBEDTLS_ERR_CCM_HW_ACCEL_FAILED is deprecated and should not be used. */
 #define MBEDTLS_ERR_CCM_HW_ACCEL_FAILED -0x0011 /**< CCM hardware accelerator failed. */