diff --git a/include/mbedtls/cipher_internal.h b/include/mbedtls/cipher_internal.h
index f696452..f1f0e2b 100644
--- a/include/mbedtls/cipher_internal.h
+++ b/include/mbedtls/cipher_internal.h
@@ -121,6 +121,7 @@
 #if defined(MBEDTLS_USE_PSA_CRYPTO)
 typedef struct
 {
+    psa_algorithm_t alg;
     psa_key_slot_t slot;
     unsigned char slot_state; /*!< 0: The slot is unset.
                                *   1: The slot is set and we own it.