diff --git a/Gemfile.lock b/Gemfile.lock
index 956aec7..a0e7e3a 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -48,7 +48,7 @@ GEM
     excon (0.54.0)
     faraday (0.9.2)
       multipart-post (>= 1.2, < 3)
-    ffi (1.9.14)
+    ffi (1.15.5)
     gssapi (1.2.0)
       ffi (>= 1.0.1)
     gyoku (1.3.1)