diff --git a/test/regression.uts b/test/regression.uts
index 7739a02bd81b488f79e74e73d93da3768a841b3b..9eaa8e21b2dca7430d3d837784908417f8393eff 100644
--- a/test/regression.uts
+++ b/test/regression.uts
@@ -7311,7 +7311,7 @@ len([ip for ip in n1]) == 2
 = in6_getLocalUniquePrefix()
 
 p = in6_getLocalUniquePrefix()
-len(p) == 16 and p.startswith("fd")
+len(inet_pton(socket.AF_INET6, p)) == 16 and p.startswith("fd")
 
 = Misc addresses manipulation functions