diff --git a/lib/coderay/tokens.rb b/lib/coderay/tokens.rb
index e7bffce2..b5f78e71 100644
--- a/lib/coderay/tokens.rb
+++ b/lib/coderay/tokens.rb
@@ -39,6 +39,9 @@ module CodeRay
   # You can serialize it to a JSON string and store it in a database, pass it
   # around to encode it more than once, send it to other algorithms...
   class Tokens < Array
+    # Remove Array#filter that is a new alias for Array#select on Ruby 2.6,
+    # for method_missing called with filter method.
+    undef_method :filter if instance_methods.include?(:filter)
     
     # The Scanner instance that created the tokens.
     attr_accessor :scanner