diff --git a/ChangeLog.d/psa-always-on.txt b/ChangeLog.d/psa-always-on.txt
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+Default behavior changes
+   * The PK, X.509, PKCS7 and TLS modules now always use the PSA subsystem
+     to perform cryptographic operations, with a few exceptions documented
+     in docs/use-psa-crypto.md. This corresponds to the behavior of
+     Mbed TLS 3.x when MBEDTLS_USE_PSA_CRYPTO is enabled. In effect,
+     MBEDTLS_USE_PSA_CRYPTO is now always enabled.
+   * psa_crypto_init() must be called before performing any cryptographic
+     operation, including indirect requests such as parsing a key or
+     certificate or starting a TLS handshake.