diff --git a/Gemfile b/Gemfile
index 82559fa731c..993c3c4b3e7 100644
--- a/Gemfile
+++ b/Gemfile
@@ -132,7 +132,7 @@ gem 'unf', '~> 0.1.4'
 gem 'seed-fu', '~> 2.3.7'
 
 # Markdown and HTML processing
-gem 'html-pipeline', '~> 2.7.1'
+gem 'html-pipeline', '~> 2.8'
 gem 'deckar01-task_list', '2.0.0'
 gem 'gitlab-markup', '~> 1.6.4'
 gem 'redcarpet', '~> 3.4'
diff --git a/Gemfile.lock b/Gemfile.lock
index 1cd336c95d0..a4784cc6499 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -394,7 +394,7 @@ GEM
     hipchat (1.5.2)
       httparty
       mimemagic
-    html-pipeline (2.7.1)
+    html-pipeline (2.8.3)
       activesupport (>= 2)
       nokogiri (>= 1.4)
     html2text (0.2.0)
@@ -1061,7 +1061,7 @@ DEPENDENCIES
   hashie-forbidden_attributes
   health_check (~> 2.6.0)
   hipchat (~> 1.5.0)
-  html-pipeline (~> 2.7.1)
+  html-pipeline (~> 2.8)
   html2text
   httparty (~> 0.13.3)
   icalendar
diff --git a/Gemfile.rails5.lock b/Gemfile.rails5.lock
index 3159942b4c5..75d9db5f29a 100644
--- a/Gemfile.rails5.lock
+++ b/Gemfile.rails5.lock
@@ -397,7 +397,7 @@ GEM
     hipchat (1.5.2)
       httparty
       mimemagic
-    html-pipeline (2.7.1)
+    html-pipeline (2.8.3)
       activesupport (>= 2)
       nokogiri (>= 1.4)
     html2text (0.2.0)
@@ -1071,7 +1071,7 @@ DEPENDENCIES
   hashie-forbidden_attributes
   health_check (~> 2.6.0)
   hipchat (~> 1.5.0)
-  html-pipeline (~> 2.7.1)
+  html-pipeline (~> 2.8)
   html2text
   httparty (~> 0.13.3)
   icalendar
diff --git a/lib/banzai/filter/sanitization_filter.rb b/lib/banzai/filter/sanitization_filter.rb
index afc2ca4e362..8275bb9e149 100644
--- a/lib/banzai/filter/sanitization_filter.rb
+++ b/lib/banzai/filter/sanitization_filter.rb
@@ -4,27 +4,20 @@ module Banzai
     #
     # Extends HTML::Pipeline::SanitizationFilter with a custom whitelist.
     class SanitizationFilter < HTML::Pipeline::SanitizationFilter
+      include Gitlab::Utils::StrongMemoize
+
       UNSAFE_PROTOCOLS = %w(data javascript vbscript).freeze
       TABLE_ALIGNMENT_PATTERN = /text-align: (?<alignment>center|left|right)/
 
       def whitelist
-        whitelist = super
-
-        customize_whitelist(whitelist)
-
-        whitelist
+        strong_memoize(:whitelist) do
+          customize_whitelist(super.dup)
+        end
       end
 
       private
 
-      def customized?(transformers)
-        transformers.last.source_location[0] == __FILE__
-      end
-
       def customize_whitelist(whitelist)
-        # Only push these customizations once
-        return if customized?(whitelist[:transformers])
-
         # Allow table alignment; we whitelist specific text-align values in a
         # transformer below
         whitelist[:attributes]['th'] = %w(style)