diff --git a/include/mbedtls/check_config.h b/include/mbedtls/check_config.h
index fd979db..1ebb706 100644
--- a/include/mbedtls/check_config.h
+++ b/include/mbedtls/check_config.h
@@ -609,6 +609,11 @@
 #error "MBEDTLS_PSA_ITS_FILE_C defined, but not all prerequisites"
 #endif
 
+#if defined(MBEDTLS_PSA_CRYPTO_KEY_ID_ENCODES_OWNER) && \
+    defined(MBEDTLS_USE_PSA_CRYPTO)
+#error "MBEDTLS_PSA_CRYPTO_KEY_ID_ENCODES_OWNER defined, but it cannot coexist with MBEDTLS_USE_PSA_CRYPTO."
+#endif
+
 #if defined(MBEDTLS_RSA_C) && ( !defined(MBEDTLS_BIGNUM_C) ||         \
     !defined(MBEDTLS_OID_C) )
 #error "MBEDTLS_RSA_C defined, but not all prerequisites"
diff --git a/include/mbedtls/config.h b/include/mbedtls/config.h
index 2ac2cc6..c930a8f 100644
--- a/include/mbedtls/config.h
+++ b/include/mbedtls/config.h
@@ -1266,7 +1266,7 @@
  * which is currently hard-coded to be int32_t.
  *
  * Note that this option is meant for internal use only and may be removed
- * without notice.
+ * without notice. It is incompatible with PSA_USE_PSA_CRYPTO.
  */
 //#define MBEDTLS_PSA_CRYPTO_KEY_ID_ENCODES_OWNER