diff --git a/Gemfile.lock b/Gemfile.lock
index c2947a4..9d0c68b 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -10,7 +10,7 @@ GEM
     diff-lcs (1.2.5)
     ethon (0.7.1)
       ffi (>= 1.3.0)
-    ffi (1.9.5)
+    ffi (1.15.5)
     rake (10.3.2)
     rspec (3.1.0)
       rspec-core (~> 3.1.0)