diff --git a/Gemfile.lock b/Gemfile.lock
index 4bf2fcb8..6dffc182 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -101,7 +101,7 @@ GEM
     nanaimo (0.4.0)
     nap (1.1.0)
     netrc (0.11.0)
-    nkf (0.2.0)
+    nkf (0.3.0)
     nokogiri (1.18.10)
       mini_portile2 (~> 2.8.2)
       racc (~> 1.4)