diff --git a/tools/libs/guest/xg_dom_core.c b/tools/libs/guest/xg_dom_core.c
index 2e4c1330ea..65975a75da 100644
--- a/tools/libs/guest/xg_dom_core.c
+++ b/tools/libs/guest/xg_dom_core.c
@@ -856,7 +856,7 @@ int xc_dom_devicetree_file(struct xc_dom_image *dom, const char *filename)
         return -1;
     return 0;
 #else
-    errno = -EINVAL;
+    errno = EINVAL;
     return -1;
 #endif
 }