diff --git a/include/mbedtls/mbedtls_config.h b/include/mbedtls/mbedtls_config.h
index 3f2937a..37af264 100644
--- a/include/mbedtls/mbedtls_config.h
+++ b/include/mbedtls/mbedtls_config.h
@@ -1469,20 +1469,24 @@
 //#define MBEDTLS_PSA_INJECT_ENTROPY
 
 /**
- * \def MBEDTLS_PSA_COPY_CALLER_BUFFERS
+ * \def MBEDTLS_PSA_ASSUME_EXCLUSIVE_BUFFERS
  *
- * Make local copies of buffers supplied by the callers of PSA functions.
+ * Assume all buffers passed to PSA functions are owned exclusively by the
+ * PSA function and are not stored in shared memory.
  *
- * This should be enabled whenever caller-supplied buffers are owned by
- * an untrusted party, for example where arguments to PSA calls are passed
+ * This option may be enabled if all buffers passed to any PSA function reside
+ * in memory that is accessible only to the PSA function during its execution.
+ *
+ * This option MUST be disabled whenever buffer arguments are in memory shared
+ * with an untrusted party, for example where arguments to PSA calls are passed
  * across a trust boundary.
  *
- * \note Enabling this option increases memory usage and code size.
+ * \note Enabling this option reduces memory usage and code size.
  *
- * \note Disabling this option causes overlap of input and output buffers
+ * \note Enabling this option causes overlap of input and output buffers
  *       not to be supported by PSA functions.
  */
-#define MBEDTLS_PSA_COPY_CALLER_BUFFERS
+//#define MBEDTLS_PSA_ASSUME_EXCLUSIVE_BUFFERS
 
 /**
  * \def MBEDTLS_RSA_NO_CRT