diff --git a/pvattest/src/uvio.c b/pvattest/src/uvio.c
index d68997be..1f784067 100644
--- a/pvattest/src/uvio.c
+++ b/pvattest/src/uvio.c
@@ -9,6 +9,7 @@
  */
 /* Must be included before any other header */
 #include "config.h"
+#include "lib/zt_common.h"
 
 #ifdef PVATTEST_COMPILE_PERFORM
 #include <stdio.h>
@@ -47,14 +48,17 @@ uvio_attest_t *build_attestation_v1_ioctl(GBytes *serialized_arcb, GBytes *user_
 	g_steal_pointer(&serialized_arcb);
 
 	if (user_data) {
-		if (g_bytes_get_size(user_data) > sizeof(uvio_attest->user_data)) {
+		size_t user_data_size = g_bytes_get_size(user_data);
+
+		if (user_data_size > sizeof(uvio_attest->user_data)) {
 			g_set_error(error, ATT_ERROR, ATT_ERR_INVALID_USER_DATA,
-				    _("User data larger than %li bytes"),
-				    sizeof(uvio_attest->user_data));
+				    _("User data %li bytes is larger than %li bytes"),
+				    user_data_size, sizeof(uvio_attest->user_data));
 			return NULL;
 		}
-		uvio_attest->user_data_len = (uint16_t)g_bytes_get_size(user_data);
-		pv_gbytes_memcpy(uvio_attest->user_data, uvio_attest->user_data_len, user_data);
+		pv_gbytes_memcpy(uvio_attest->user_data, sizeof(uvio_attest->user_data), user_data);
+		STATIC_ASSERT(sizeof(uvio_attest->user_data) <= UINT16_MAX);
+		uvio_attest->user_data_len = (uint16_t)user_data_size;
 	}
 
 	uvio_attest->meas_addr = PTR_TO_U64(g_malloc0(measurement_size));