diff --git a/themes/petitions_responsive/Gemfile.lock b/themes/petitions_responsive/Gemfile.lock
index 26b7bc203..2385c1493 100644
--- a/themes/petitions_responsive/Gemfile.lock
+++ b/themes/petitions_responsive/Gemfile.lock
@@ -4,7 +4,7 @@ GEM
     bourbon (4.2.6)
       sass (~> 3.4)
       thor (~> 0.19)
-    ffi (1.9.6)
+    ffi (1.15.5)
     neat (1.7.2)
       bourbon (>= 4.0)
       sass (>= 3.3)