diff --git a/library/psa_crypto.c b/library/psa_crypto.c
index d88836b..7a6bb37 100644
--- a/library/psa_crypto.c
+++ b/library/psa_crypto.c
@@ -1201,7 +1201,7 @@
                                 MBEDTLS_PSA_KA_MASK_DUAL_USE );
 
 #if defined(MBEDTLS_PSA_CRYPTO_SE_C)
-    if( psa_key_slot_is_external( slot ) )
+    if( psa_get_se_driver_entry( slot->attr.lifetime ) != NULL )
         psa_set_key_slot_number( attributes,
                                  psa_key_slot_get_slot_number( slot ) );
 #endif /* MBEDTLS_PSA_CRYPTO_SE_C */