diff --git a/include/psa/crypto_struct.h b/include/psa/crypto_struct.h
index eba4862..2975bdc 100644
--- a/include/psa/crypto_struct.h
+++ b/include/psa/crypto_struct.h
@@ -106,7 +106,7 @@
     uint8_t block_size;
     union
     {
-        unsigned dummy; /* Make the union non-empty even with no supported algorithms. */
+        mbedtls_cipher_context_t cipher;
     } ctx;
 };