diff --git a/Gemfile.lock b/Gemfile.lock
index 1c61049..83e09a2 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -4,7 +4,7 @@ GEM
     addressable (2.5.2)
       public_suffix (>= 2.0.2, < 4.0)
     colorator (1.1.0)
-    ffi (1.9.18)
+    ffi (1.15.0)
     forwardable-extended (2.6.0)
     jekyll (3.4.5)
       addressable (~> 2.4)