diff --git a/include/psa/crypto_extra.h b/include/psa/crypto_extra.h
index b6f5adc..7f08857 100644
--- a/include/psa/crypto_extra.h
+++ b/include/psa/crypto_extra.h
@@ -48,7 +48,6 @@
 void mbedtls_psa_crypto_free( void );
 
 
-#if ( defined(MBEDTLS_ENTROPY_NV_SEED) && defined(MBEDTLS_PSA_HAS_ITS_IO) )
 /**
  * \brief Inject an initial entropy seed for the random generator into
  *        secure storage.
@@ -89,13 +88,20 @@
  *
  * This is an Mbed TLS extension.
  *
- * \param seed[in]      Buffer containing the seed value to inject.
- * \param seed_size     Size of the \p seed buffer.
- *                      The size of the seed in bytes must be greater
- *                      or equal to both #MBEDTLS_ENTROPY_MIN_PLATFORM
- *                      and #MBEDTLS_ENTROPY_BLOCK_SIZE.
- *                      It must be less or equal to
- *                      #MBEDTLS_ENTROPY_MAX_SEED_SIZE.
+ * \note This function is only available on the following platforms:
+ * * If the compile-time options MBEDTLS_ENTROPY_NV_SEED and
+ *   MBEDTLS_PSA_HAS_ITS_IO are both enabled. Note that you
+ *   must provide compatible implementations of mbedtls_nv_seed_read
+ *   and mbedtls_nv_seed_write.
+ * * In a client-server integration of PSA Cryptography, on the client side,
+ *   if the server supports this feature.
+ * \param[in] seed          Buffer containing the seed value to inject.
+ * \param[in] seed_size     Size of the \p seed buffer.
+ *                          The size of the seed in bytes must be greater
+ *                          or equal to both #MBEDTLS_ENTROPY_MIN_PLATFORM
+ *                          and #MBEDTLS_ENTROPY_BLOCK_SIZE.
+ *                          It must be less or equal to
+ *                          #MBEDTLS_ENTROPY_MAX_SEED_SIZE.
  *
  * \retval #PSA_SUCCESS
  *         The seed value was injected successfully. The random generator
@@ -114,7 +120,6 @@
 psa_status_t mbedtls_psa_inject_entropy(const unsigned char *seed,
                                         size_t seed_size);
 
-#endif
 
 #ifdef __cplusplus
 }