diff --git a/plugins/uefi/fu-uefi-vars.c b/plugins/uefi/fu-uefi-vars.c
index da32e0367..d776d05cb 100644
--- a/plugins/uefi/fu-uefi-vars.c
+++ b/plugins/uefi/fu-uefi-vars.c
@@ -224,7 +224,7 @@ fu_uefi_vars_get_data (const gchar *guid, const gchar *name, guint8 **data,
 	if (data_sz != NULL)
 		*data_sz = data_sz_tmp;
 	if (data != NULL) {
-		g_autofree gchar *data_tmp = g_malloc0 (data_sz_tmp);
+		g_autofree guint8 *data_tmp = g_malloc0 (data_sz_tmp);
 		if (!g_input_stream_read_all (istr, data_tmp, data_sz_tmp,
 					      NULL, NULL, error)) {
 			g_prefix_error (error, "failed to read data: ");