diff --git a/include/mbedtls/config_adjust_legacy_crypto.h b/include/mbedtls/config_adjust_legacy_crypto.h
index c6b7f8ef3..696266c6f 100644
--- a/include/mbedtls/config_adjust_legacy_crypto.h
+++ b/include/mbedtls/config_adjust_legacy_crypto.h
@@ -22,6 +22,20 @@
 #ifndef MBEDTLS_CONFIG_ADJUST_LEGACY_CRYPTO_H
 #define MBEDTLS_CONFIG_ADJUST_LEGACY_CRYPTO_H
 
+/* Auto-enable CIPHER_C when any of the unauthenticated ciphers is builtin
+ * in PSA. */
+#if defined(MBEDTLS_PSA_CRYPTO_C) && \
+    (defined(MBEDTLS_PSA_BUILTIN_ALG_STREAM_CIPHER) || \
+    defined(MBEDTLS_PSA_BUILTIN_ALG_CTR) || \
+    defined(MBEDTLS_PSA_BUILTIN_ALG_CFB) || \
+    defined(MBEDTLS_PSA_BUILTIN_ALG_OFB) || \
+    defined(MBEDTLS_PSA_BUILTIN_ALG_ECB_NO_PADDING) || \
+    defined(MBEDTLS_PSA_BUILTIN_ALG_CBC_NO_PADDING) || \
+    defined(MBEDTLS_PSA_BUILTIN_ALG_CBC_PKCS7) || \
+    defined(MBEDTLS_PSA_BUILTIN_ALG_CCM_STAR_NO_TAG))
+#define MBEDTLS_CIPHER_C
+#endif
+
 /* Auto-enable MBEDTLS_MD_LIGHT based on MBEDTLS_MD_C.
  * This allows checking for MD_LIGHT rather than MD_LIGHT || MD_C.
  */
diff --git a/include/mbedtls/mbedtls_config.h b/include/mbedtls/mbedtls_config.h
index 94e21e271..6a5828c74 100644
--- a/include/mbedtls/mbedtls_config.h
+++ b/include/mbedtls/mbedtls_config.h
@@ -2579,6 +2579,8 @@
  *          library/ssl_ciphersuites.c
  *          library/ssl_msg.c
  *          library/ssl_ticket.c (unless MBEDTLS_USE_PSA_CRYPTO is enabled)
+ * Auto-enabled by: MBEDTLS_PSA_CRYPTO_C depending on which ciphers are enabled
+ *                  (see the documentation of that option for details).
  *
  * Uncomment to enable generic cipher wrappers.
  */
@@ -3168,7 +3170,9 @@
  * Requires: either MBEDTLS_CTR_DRBG_C and MBEDTLS_ENTROPY_C,
  *           or MBEDTLS_HMAC_DRBG_C and MBEDTLS_ENTROPY_C,
  *           or MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG.
- *
+ * Auto-enables: MBEDTLS_CIPHER_C if any unauthenticated (ie, non-AEAD) cipher
+ *               is enabled in PSA (unless it's fully accelerated, see
+ *               docs/driver-only-builds.md about that).
  */
 #define MBEDTLS_PSA_CRYPTO_C