diff --git a/Gemfile.lock b/Gemfile.lock
index 7485708..b597820 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,5 +1,5 @@
 GIT
-  remote: git://github.com/billthompson/birch.git
+  remote: https://github.com/billthompson/birch.git
   revision: dc6c8e5d667f6c946c989f4d8f159f622d3bf77a
   branch: birch-ruby22
   specs:
@@ -137,7 +137,7 @@ GEM
       thor (>= 0.14, < 2.0)
     json (2.1.0)
     jwt (2.1.0)
-    libv8 (6.7.288.46.1)
+    libv8-node (15.14.0.0)
     loggability (0.14.0)
     loofah (2.2.3)
       crass (~> 1.0.2)
@@ -154,11 +154,13 @@ GEM
       railties (>= 3.0)
     method_source (0.9.2)
     mime-types (1.25.1)
-    mimemagic (0.3.3)
+    mimemagic (0.3.10)
+      nokogiri (~> 1)
+      rake
     mini_mime (1.0.1)
     mini_portile2 (2.4.0)
-    mini_racer (0.2.4)
-      libv8 (>= 6.3)
+    mini_racer (0.4.0)
+      libv8-node (~> 15.14.0.0)
     minitest (5.11.3)
     multi_json (1.13.1)
     multi_xml (0.6.0)