diff --git a/app/models/article.rb b/app/models/article.rb
index 0d968a1e1..441fae5c5 100644
--- a/app/models/article.rb
+++ b/app/models/article.rb
@@ -31,7 +31,7 @@ class Article < ApplicationRecord
   validate :validate_tag
   validate :validate_video
   validates :video_state, inclusion: { in: %w(PROGRESSING COMPLETED) }, allow_nil: true
-  validates :cached_tag_list, length: { maximum: 64 }
+  validates :cached_tag_list, length: { maximum: 86 }
   validates :main_image, url: { allow_blank: true, schemes: ["https", "http"] }
   validates :main_image_background_hex_color, format: /\A#([A-Fa-f0-9]{6}|[A-Fa-f0-9]{3})\z/
   validates :video, url: { allow_blank: true, schemes: ["https", "http"] }
@@ -414,7 +414,7 @@ class Article < ApplicationRecord
     return errors.add(:tag_list, "exceed the maximum of 4 tags") if tag_list.length > 4
     tag_list.each do |tag|
       if tag.length > 20
-        errors.add(:tag, "\"#{tag}\" is too long (maximum is 16 characters)")
+        errors.add(:tag, "\"#{tag}\" is too long (maximum is 20 characters)")
       end
     end
   end
diff --git a/spec/models/article_spec.rb b/spec/models/article_spec.rb
index f671fb60e..8fe284209 100644
--- a/spec/models/article_spec.rb
+++ b/spec/models/article_spec.rb
@@ -17,7 +17,7 @@ RSpec.describe Article, type: :model do
   it { is_expected.to validate_uniqueness_of(:feed_source_url).allow_blank }
   it { is_expected.to validate_presence_of(:title) }
   it { is_expected.to validate_length_of(:title).is_at_most(128) }
-  it { is_expected.to validate_length_of(:cached_tag_list).is_at_most(64) }
+  it { is_expected.to validate_length_of(:cached_tag_list).is_at_most(86) }
   it { is_expected.to belong_to(:user) }
   it { is_expected.to belong_to(:organization) }
   it { is_expected.to belong_to(:collection) }