diff --git a/tools/libxl/libxl_create.c b/tools/libxl/libxl_create.c
index ce6a55e..6486156 100644
--- a/tools/libxl/libxl_create.c
+++ b/tools/libxl/libxl_create.c
@@ -461,7 +461,7 @@ static int store_libxl_entry(libxl__gc *gc, uint32_t domid,
 
     path = libxl__xs_libxl_path(gc, domid);
     path = libxl__sprintf(gc, "%s/dm-version", path);
-    return libxl__xs_write(gc, XBT_NULL, path, libxl__strdup(gc,
+    return libxl__xs_write(gc, XBT_NULL, path, "%s", libxl__strdup(gc,
         libxl_device_model_version_to_string(dm_info->device_model_version)));
 }
 
diff --git a/tools/libxl/libxl_device.c b/tools/libxl/libxl_device.c
index a53fb70..1db395c 100644
--- a/tools/libxl/libxl_device.c
+++ b/tools/libxl/libxl_device.c
@@ -516,7 +516,7 @@ int libxl__devices_destroy(libxl__gc *gc, uint32_t domid, int force)
         for (j = 0; j < num_devs; j++) {
             path = libxl__sprintf(gc, "/local/domain/%d/device/%s/%s/backend",
                                   domid, kinds[i], devs[j]);
-            path = libxl__xs_read(gc, XBT_NULL, libxl__sprintf(gc, path));
+            path = libxl__xs_read(gc, XBT_NULL, libxl__sprintf(gc, "%s", path));
             if (path && libxl__parse_backend_path(gc, path, &dev) == 0) {
                 dev.domid = domid;
                 dev.kind = kind;