diff --git a/library/psa_crypto_driver_wrappers.c b/library/psa_crypto_driver_wrappers.c
index 07888f1..e0c86cf 100644
--- a/library/psa_crypto_driver_wrappers.c
+++ b/library/psa_crypto_driver_wrappers.c
@@ -238,7 +238,6 @@
 #endif /* PSA_CRYPTO_DRIVER_PRESENT */
 }
 
-#if defined(PSA_CRYPTO_ACCELERATOR_DRIVER_PRESENT)
 /** Get the key buffer size for the key material of a generated key in the
  *  case of an opaque driver without storage.
  *
@@ -254,7 +253,7 @@
  *         The type and/or the size in bits of the key or the combination of
  *         the two is not supported.
  */
-static psa_status_t get_key_buffer_size(
+psa_status_t psa_driver_wrapper_get_key_buffer_size(
     const psa_key_attributes_t *attributes,
     size_t *key_buffer_size )
 {
@@ -301,10 +300,11 @@
 #endif /* PSA_CRYPTO_DRIVER_TEST */
 
         default:
+            (void)key_type;
+            (void)key_bits;
             return( PSA_ERROR_NOT_SUPPORTED );
     }
 }
-#endif /* PSA_CRYPTO_ACCELERATOR_DRIVER_PRESENT */
 
 psa_status_t psa_driver_wrapper_generate_key( const psa_key_attributes_t *attributes,
                                               psa_key_slot_t *slot )
@@ -350,7 +350,8 @@
         }
         else
         {
-            status = get_key_buffer_size( attributes, &export_size );
+            status = psa_driver_wrapper_get_key_buffer_size( attributes,
+                                                             &export_size );
             if( status != PSA_SUCCESS )
                 return( status );
         }
diff --git a/library/psa_crypto_driver_wrappers.h b/library/psa_crypto_driver_wrappers.h
index 27d8b64..b9bb53e 100644
--- a/library/psa_crypto_driver_wrappers.h
+++ b/library/psa_crypto_driver_wrappers.h
@@ -63,6 +63,10 @@
     const uint8_t *key_buffer, size_t key_buffer_size,
     uint8_t *data, size_t data_size, size_t *data_length );
 
+psa_status_t psa_driver_wrapper_get_key_buffer_size(
+    const psa_key_attributes_t *attributes,
+    size_t *key_buffer_size );
+
 psa_status_t psa_driver_wrapper_generate_key(
     const psa_key_attributes_t *attributes,
     psa_key_slot_t *slot );