diff --git a/Gemfile.lock b/Gemfile.lock
index e9110a0..22c8c98 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -57,12 +57,11 @@ GEM
       tins (~> 1.6.0)
     crack (0.4.3)
       safe_yaml (~> 1.0.0)
-    devise (3.5.6)
+    devise (4.0.0)
       bcrypt (~> 3.0)
       orm_adapter (~> 0.1)
-      railties (>= 3.2.6, < 5)
+      railties (>= 4.1.0, < 5.1)
       responders
-      thread_safe (~> 0.1)
       warden (~> 1.2.3)
     docile (1.1.5)
     erubis (2.7.0)