diff --git a/.travis.yml b/.travis.yml
index e6ef702a4..42b1c6504 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,6 +1,6 @@
 language: ruby
 rvm:
-  - 2.3.1
+  - 2.5.8
 
 cache: bundler
 
diff --git a/Gemfile.lock b/Gemfile.lock
index cf51b93a2..4818834c0 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -59,14 +59,16 @@ GEM
       rb-fsevent (~> 0.10, >= 0.10.3)
       rb-inotify (~> 0.9, >= 0.9.10)
     mercenary (0.3.6)
-    mini_portile2 (2.4.0)
+    mini_portile2 (2.5.0)
     minitest (5.14.1)
-    nokogiri (1.10.10)
-      mini_portile2 (~> 2.4.0)
+    nokogiri (1.11.1)
+      mini_portile2 (~> 2.5.0)
+      racc (~> 1.4)
     parallel (1.12.1)
     pathutil (0.16.2)
       forwardable-extended (~> 2.6)
     public_suffix (4.0.5)
+    racc (1.5.2)
     rake (12.3.3)
     rb-fsevent (0.10.4)
     rb-inotify (0.10.1)