diff --git a/Gemfile.lock b/Gemfile.lock
index 6b1eced..f7fa3d9 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -10,8 +10,8 @@ GEM
       http_parser.rb (~> 0.6.0)
     eventmachine (1.2.7)
     eventmachine (1.2.7-x64-mingw32)
-    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)
     http_parser.rb (0.6.0)
     i18n (0.9.5)