diff --git a/Gemfile.lock b/Gemfile.lock
index bf4b9ef..6f86f2a 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -8,20 +8,15 @@ GEM
       mime (>= 0.1)
     gmail_xoauth (0.4.1)
       oauth (>= 0.3.6)
-    mail (2.5.4)
-      mime-types (~> 1.16)
-      treetop (~> 1.4.8)
+    mail (2.7.1)
+      mini_mime (>= 0.1.1)
     method_source (0.9.2)
     mime (0.3.0)
-    mime-types (1.25.1)
+    mini_mime (1.0.2)
     oauth (0.4.7)
-    polyglot (0.3.4)
     pry (0.12.2)
       coderay (~> 1.1.0)
       method_source (~> 0.9.0)
-    treetop (1.4.15)
-      polyglot
-      polyglot (>= 0.3.1)
 
 PLATFORMS
   ruby