diff --git a/Gemfile.lock b/Gemfile.lock
index 18a92eb54..bd372118f 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -257,7 +257,7 @@ GEM
     liquid (3.0.6)
     loofah (2.0.3)
       nokogiri (>= 1.5.9)
-    mail (2.6.5)
+    mail (2.6.6)
       mime-types (>= 1.16, < 4)
     method_source (0.8.2)
     mime-types (3.1)