diff --git a/Gemfile b/Gemfile
index 6957d38945ad1265ba0292d0f259b61b7f09a8ab..ba77ced7d7a6d8ab3f716c2f8fd1f18535dbf21e 100644
--- a/Gemfile
+++ b/Gemfile
@@ -5,9 +5,6 @@ git_source(:github) do |repo_name|
   "https://github.com/#{repo_name}.git"
 end
 
-# Necessary for an unknown reason in production
-gem 'mini_portile2'
-
 # The central piece of this application: the month calendar view
 gem 'simple_calendar'
 # The recurrence management library
diff --git a/Gemfile.lock b/Gemfile.lock
index 5eda0904ef2595528e5f137ce1224fecf0d8283e..b1d06ddd42cc41c658a07127be09d06a28eab672 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -77,7 +77,7 @@ GEM
       rack (>= 1.0.0)
       rack-test (>= 0.5.4)
       xpath (>= 2.0, < 4.0)
-    childprocess (0.8.0)
+    childprocess (0.9.0)
       ffi (~> 1.0, >= 1.0.11)
     coderay (1.1.2)
     coffee-rails (4.2.2)
@@ -89,13 +89,13 @@ GEM
     coffee-script-source (1.12.2)
     concurrent-ruby (1.0.5)
     crass (1.0.3)
-    devise (4.4.1)
+    devise (4.4.2)
       bcrypt (~> 3.0)
       orm_adapter (~> 0.1)
-      railties (>= 4.1.0, < 5.2)
+      railties (>= 4.1.0, < 6.0)
       responders
       warden (~> 1.2.3)
-    devise-i18n (1.6.0)
+    devise-i18n (1.6.1)
       devise (>= 4.4)
     differ (0.1.2)
     domain_name (0.5.20170404)
@@ -106,7 +106,7 @@ GEM
     email_validator (1.6.0)
       activemodel
     equalizer (0.0.11)
-    erubi (1.7.0)
+    erubi (1.7.1)
     erubis (2.7.0)
     eventmachine (1.2.5)
     execjs (2.7.0)
@@ -119,7 +119,7 @@ GEM
     formtastic (3.1.5)
       actionpack (>= 3.2.13)
     formtastic_i18n (0.6.0)
-    geocoder (1.4.6)
+    geocoder (1.4.7)
     globalid (0.4.1)
       activesupport (>= 4.2.0)
     guard (2.14.2)
@@ -188,7 +188,7 @@ GEM
       http_parser.rb (~> 0.6.0)
     http-cookie (1.0.3)
       domain_name (~> 0.5)
-    http-form_data (2.0.0)
+    http-form_data (2.1.0)
     http_accept_language (2.1.1)
     http_parser.rb (0.6.0)
     i18n (0.9.5)
@@ -240,7 +240,6 @@ GEM
       actionpack (>= 3.2.0, < 5.3)
     method_source (0.9.0)
     mini_mime (1.0.0)
-    mini_portile2 (2.3.0)
     minitest (5.11.3)
     modernizr-rails (2.7.1)
     multi_json (1.13.1)
@@ -248,9 +247,8 @@ GEM
     mysql2 (0.4.10)
     naught (1.1.0)
     nenv (0.3.0)
-    nio4r (2.2.0)
+    nio4r (2.3.0)
     nokogiri (1.8.2)
-      mini_portile2 (~> 2.3.0)
     notiffany (0.1.1)
       nenv (~> 0.1)
       shellany (~> 0.0)
@@ -259,7 +257,7 @@ GEM
       activerecord (>= 4.2, < 5.2)
       request_store (~> 1.1)
     parallel (1.12.1)
-    parser (2.5.0.2)
+    parser (2.5.0.4)
       ast (~> 2.4.0)
     piwik_analytics (1.0.2)
       actionpack
@@ -272,7 +270,7 @@ GEM
       coderay (~> 1.1.0)
       method_source (~> 0.9.0)
     public_suffix (3.0.2)
-    puma (3.11.2)
+    puma (3.11.3)
     rack (2.0.4)
     rack-livereload (0.3.16)
       rack
@@ -320,19 +318,19 @@ GEM
       activesupport (>= 3.0)
       i18n
       polyamorous (~> 1.3.2)
-    rb-fsevent (0.10.2)
+    rb-fsevent (0.10.3)
     rb-inotify (0.9.10)
       ffi (>= 0.5.0, < 2)
-    rdoc (6.0.1)
+    rdoc (6.0.2)
     ref (2.0.0)
-    request_store (1.4.0)
+    request_store (1.4.1)
       rack (>= 1.4)
     responders (2.4.0)
       actionpack (>= 4.2.0, < 5.3)
       railties (>= 4.2.0, < 5.3)
-    rubocop (0.52.1)
+    rubocop (0.53.0)
       parallel (~> 1.10)
-      parser (>= 2.4.0.2, < 3.0)
+      parser (>= 2.5)
       powerpack (~> 0.1)
       rainbow (>= 2.2.2, < 4.0)
       ruby-progressbar (~> 1.7)
@@ -355,7 +353,7 @@ GEM
       tilt (>= 1.1, < 3)
     sdoc (1.0.0)
       rdoc (>= 5.0)
-    selenium-webdriver (3.9.0)
+    selenium-webdriver (3.11.0)
       childprocess (~> 0.5)
       rubyzip (~> 1.2)
     sexp_processor (4.10.1)
@@ -408,7 +406,7 @@ GEM
       simple_oauth (~> 0.3.0)
     tzinfo (1.2.5)
       thread_safe (~> 0.1)
-    uglifier (4.1.6)
+    uglifier (4.1.8)
       execjs (>= 0.3.0, < 3)
     unf (0.1.4)
       unf_ext
@@ -465,7 +463,6 @@ DEPENDENCIES
   kramdown
   listen (>= 3.0.5, < 3.2)
   meta-tags
-  mini_portile2
   modernizr-rails
   mysql2
   paper_trail
@@ -497,4 +494,4 @@ DEPENDENCIES
   web-console (>= 3.3.0)
 
 BUNDLED WITH
-   1.15.1
+   1.16.1