diff --git a/Gemfile.lock b/Gemfile.lock
index 33a956b..3fa7788 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -2,11 +2,66 @@ PATH
   remote: .
   specs:
     fullcalendar (3.8.0)
+      momentjs-rails (~> 2.20.1)
 
 GEM
   remote: https://rubygems.org/
   specs:
-    rake (10.5.0)
+    actionpack (6.0.2.1)
+      actionview (= 6.0.2.1)
+      activesupport (= 6.0.2.1)
+      rack (~> 2.0, >= 2.0.8)
+      rack-test (>= 0.6.3)
+      rails-dom-testing (~> 2.0)
+      rails-html-sanitizer (~> 1.0, >= 1.2.0)
+    actionview (6.0.2.1)
+      activesupport (= 6.0.2.1)
+      builder (~> 3.1)
+      erubi (~> 1.4)
+      rails-dom-testing (~> 2.0)
+      rails-html-sanitizer (~> 1.1, >= 1.2.0)
+    activesupport (6.0.2.1)
+      concurrent-ruby (~> 1.0, >= 1.0.2)
+      i18n (>= 0.7, < 2)
+      minitest (~> 5.1)
+      tzinfo (~> 1.1)
+      zeitwerk (~> 2.2)
+    builder (3.2.4)
+    concurrent-ruby (1.1.6)
+    crass (1.0.6)
+    erubi (1.9.0)
+    i18n (1.8.2)
+      concurrent-ruby (~> 1.0)
+    loofah (2.4.0)
+      crass (~> 1.0.2)
+      nokogiri (>= 1.5.9)
+    method_source (0.9.2)
+    mini_portile2 (2.4.0)
+    minitest (5.14.0)
+    momentjs-rails (2.20.1)
+      railties (>= 3.1)
+    nokogiri (1.10.8)
+      mini_portile2 (~> 2.4.0)
+    rack (2.2.2)
+    rack-test (1.1.0)
+      rack (>= 1.0, < 3)
+    rails-dom-testing (2.0.3)
+      activesupport (>= 4.2.0)
+      nokogiri (>= 1.6)
+    rails-html-sanitizer (1.3.0)
+      loofah (~> 2.3)
+    railties (6.0.2.1)
+      actionpack (= 6.0.2.1)
+      activesupport (= 6.0.2.1)
+      method_source
+      rake (>= 0.8.7)
+      thor (>= 0.20.3, < 2.0)
+    rake (13.0.1)
+    thor (1.0.1)
+    thread_safe (0.3.6)
+    tzinfo (1.2.6)
+      thread_safe (~> 0.1)
+    zeitwerk (2.2.2)
 
 PLATFORMS
   ruby
@@ -14,7 +69,7 @@ PLATFORMS
 DEPENDENCIES
   bundler (~> 1.16)
   fullcalendar!
-  rake (~> 10.0)
+  rake (~> 13.0)
 
 BUNDLED WITH
    1.16.1
diff --git a/fullcalendar.gemspec b/fullcalendar.gemspec
index 689dfe1..f25c58f 100644
--- a/fullcalendar.gemspec
+++ b/fullcalendar.gemspec
@@ -24,5 +24,5 @@ Gem::Specification.new do |spec|
   spec.add_runtime_dependency 'momentjs-rails', '~> 2.20.1'
 
   spec.add_development_dependency "bundler", "~> 1.16"
-  spec.add_development_dependency "rake", "~> 10.0"
+  spec.add_development_dependency "rake", "~> 13.0"
 end