diff --git a/include/psa/crypto_extra.h b/include/psa/crypto_extra.h
index f0c7979..71adb93 100644
--- a/include/psa/crypto_extra.h
+++ b/include/psa/crypto_extra.h
@@ -232,9 +232,9 @@
     /** Number of slots that are not used for anything. */
     size_t empty_slots;
     /** Largest key id value among open keys in internal persistent storage. */
-    psa_app_key_id_t max_open_internal_key_id;
+    psa_key_id_t max_open_internal_key_id;
     /** Largest key id value among open keys in secure elements. */
-    psa_app_key_id_t max_open_external_key_id;
+    psa_key_id_t max_open_external_key_id;
 } mbedtls_psa_stats_t;
 
 /** \brief Get statistics about
diff --git a/include/psa/crypto_platform.h b/include/psa/crypto_platform.h
index bd3dc10..0bebb08 100644
--- a/include/psa/crypto_platform.h
+++ b/include/psa/crypto_platform.h
@@ -47,25 +47,6 @@
 /* Integral type representing a key handle. */
 typedef uint16_t psa_key_handle_t;
 
-/* This implementation distinguishes *application key identifiers*, which
- * are the key identifiers specified by the application, from
- * *key file identifiers*, which are the key identifiers that the library
- * sees internally. The two types can be different if there is a remote
- * call layer between the application and the library which supports
- * multiple client applications that do not have access to each others'
- * keys. The point of having different types is that the key file
- * identifier may encode not only the key identifier specified by the
- * application, but also the the identity of the application.
- *
- * Note that this is an internal concept of the library and the remote
- * call layer. The application itself never sees anything other than
- * #psa_app_key_id_t with its standard definition.
- */
-
-/* The application key identifier is always what the application sees as
- * #psa_key_id_t. */
-typedef uint32_t psa_app_key_id_t;
-
 #if defined(MBEDTLS_PSA_CRYPTO_KEY_FILE_ID_ENCODES_OWNER)
 
 #if defined(PSA_CRYPTO_SECURE)
diff --git a/include/psa/crypto_types.h b/include/psa/crypto_types.h
index 4603a1d..a8becb7 100644
--- a/include/psa/crypto_types.h
+++ b/include/psa/crypto_types.h
@@ -233,14 +233,10 @@
  * - 0 is reserved as an invalid key identifier.
  * - Key identifiers outside these ranges are reserved for future use.
  */
-/* Implementation-specific quirk: The Mbed Crypto library can be built as
- * part of a multi-client service that exposes the PSA Crypto API in each
- * client and encodes the client identity in the key id argument of functions
- * such as psa_open_key(). */
-#if !defined(MBEDTLS_PSA_CRYPTO_KEY_FILE_ID_ENCODES_OWNER)
 typedef uint32_t psa_key_id_t;
-typedef psa_key_id_t psa_key_file_id_t;
 
+#if !defined(MBEDTLS_PSA_CRYPTO_KEY_FILE_ID_ENCODES_OWNER)
+typedef psa_key_id_t psa_key_file_id_t;
 #define PSA_KEY_ID_INIT 0
 #define PSA_KEY_FILE_GET_KEY_ID( id ) ( id )
 
@@ -258,9 +254,14 @@
 }
 
 #else /* MBEDTLS_PSA_CRYPTO_KEY_FILE_ID_ENCODES_OWNER */
+/* Implementation-specific: The Mbed Crypto library can be built as
+ * part of a multi-client service that exposes the PSA Crypto API in each
+ * client and encodes the client identity in the key id argument of functions
+ * such as psa_open_key().
+ */
 typedef struct
 {
-    uint32_t key_id;
+    psa_key_id_t key_id;
     psa_key_owner_id_t owner;
 } psa_key_file_id_t;
 
@@ -273,7 +274,7 @@
  * \param key_id   Identifier of the key.
  */
 static inline psa_key_file_id_t psa_key_file_id_make(
-    psa_key_owner_id_t owner_id, uint32_t key_id )
+    psa_key_owner_id_t owner_id, psa_key_id_t key_id )
 {
     return( (psa_key_file_id_t){ .key_id = key_id,
                                  .owner = owner_id } );
diff --git a/include/psa/crypto_values.h b/include/psa/crypto_values.h
index a940711..02e9c00 100644
--- a/include/psa/crypto_values.h
+++ b/include/psa/crypto_values.h
@@ -1636,16 +1636,16 @@
 
 /** The minimum value for a key identifier chosen by the application.
  */
-#define PSA_KEY_ID_USER_MIN                     ((psa_app_key_id_t)0x00000001)
+#define PSA_KEY_ID_USER_MIN                     ((psa_key_id_t)0x00000001)
 /** The maximum value for a key identifier chosen by the application.
  */
-#define PSA_KEY_ID_USER_MAX                     ((psa_app_key_id_t)0x3fffffff)
+#define PSA_KEY_ID_USER_MAX                     ((psa_key_id_t)0x3fffffff)
 /** The minimum value for a key identifier chosen by the implementation.
  */
-#define PSA_KEY_ID_VENDOR_MIN                   ((psa_app_key_id_t)0x40000000)
+#define PSA_KEY_ID_VENDOR_MIN                   ((psa_key_id_t)0x40000000)
 /** The maximum value for a key identifier chosen by the implementation.
  */
-#define PSA_KEY_ID_VENDOR_MAX                   ((psa_app_key_id_t)0x7fffffff)
+#define PSA_KEY_ID_VENDOR_MAX                   ((psa_key_id_t)0x7fffffff)
 
 /**@}*/