diff --git a/library/psa_crypto_se.h b/library/psa_crypto_se.h
index 08e658c..378c78f 100644
--- a/library/psa_crypto_se.h
+++ b/library/psa_crypto_se.h
@@ -171,4 +171,13 @@
  */
 psa_status_t psa_destroy_se_persistent_data( psa_key_lifetime_t lifetime );
 
+
+/** The storage representation of a key whose data is in a secure element.
+ */
+typedef struct
+{
+    uint8_t slot_number[sizeof( psa_key_slot_number_t )];
+    uint8_t bits[sizeof( psa_key_bits_t )];
+} psa_se_key_data_storage_t;
+
 #endif /* PSA_CRYPTO_SE_H */