diff --git a/Gemfile.lock b/Gemfile.lock
index 83d506e2..1cb34fdc 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -23,8 +23,8 @@ GEM
     excon (0.71.0)
     faraday (0.15.4)
       multipart-post (>= 1.2, < 3)
-    ffi (1.9.25)
-    ffi (1.9.25-x64-mingw32)
+    ffi (1.15.5)
+    ffi (1.15.5-x64-mingw32)
     forwardable-extended (2.6.0)
     highline (2.0.1)
     html-proofer (3.9.1)