diff --git a/app/models/commit.rb b/app/models/commit.rb
index d0dbe009d0d1833d0339b88e729a60a9d0ffb3d0..d09876a07d92842a5d93896fbe80f3251f75b0f1 100644
--- a/app/models/commit.rb
+++ b/app/models/commit.rb
@@ -74,14 +74,14 @@ class Commit
   #
   # This pattern supports cross-project references.
   def self.reference_pattern
-    %r{
+    @reference_pattern ||= %r{
       (?:#{Project.reference_pattern}#{reference_prefix})?
       (?<commit>\h{7,40})
     }x
   end
 
   def self.link_reference_pattern
-    super("commit", /(?<commit>\h{7,40})/)
+    @link_reference_pattern ||= super("commit", /(?<commit>\h{7,40})/)
   end
 
   def to_reference(from_project = nil)
diff --git a/app/models/commit_range.rb b/app/models/commit_range.rb
index 289dbc57287741ec06b7e4b2a095f03593524358..51673897d98849fb9f5b07e54ecc12c74c86b126 100644
--- a/app/models/commit_range.rb
+++ b/app/models/commit_range.rb
@@ -43,14 +43,14 @@ class CommitRange
   #
   # This pattern supports cross-project references.
   def self.reference_pattern
-    %r{
+    @reference_pattern ||= %r{
       (?:#{Project.reference_pattern}#{reference_prefix})?
       (?<commit_range>#{STRICT_PATTERN})
     }x
   end
 
   def self.link_reference_pattern
-    super("compare", /(?<commit_range>#{PATTERN})/)
+    @link_reference_pattern ||= super("compare", /(?<commit_range>#{PATTERN})/)
   end
 
   # Initialize a CommitRange
diff --git a/app/models/external_issue.rb b/app/models/external_issue.rb
index 2ca79df0a29a9aeecbe5a3602fe28506d6daac75..b8585d4e57742781cc6b73759f9b386eb7e8612a 100644
--- a/app/models/external_issue.rb
+++ b/app/models/external_issue.rb
@@ -31,7 +31,7 @@ class ExternalIssue
 
   # Pattern used to extract `JIRA-123` issue references from text
   def self.reference_pattern
-    %r{(?<issue>\b([A-Z][A-Z0-9_]+-)\d+)}
+    @reference_pattern ||= %r{(?<issue>\b([A-Z][A-Z0-9_]+-)\d+)}
   end
 
   def to_reference(_from_project = nil)
diff --git a/app/models/issue.rb b/app/models/issue.rb
index ed960cb39f44beff148345dbb6f91f865c9c951e..e064b0f8b955bb0c52f9aa0d90e9cf68dd8894e7 100644
--- a/app/models/issue.rb
+++ b/app/models/issue.rb
@@ -73,14 +73,14 @@ class Issue < ActiveRecord::Base
   #
   # This pattern supports cross-project references.
   def self.reference_pattern
-    %r{
+    @reference_pattern ||= %r{
       (#{Project.reference_pattern})?
       #{Regexp.escape(reference_prefix)}(?<issue>\d+)
     }x
   end
 
   def self.link_reference_pattern
-    super("issues", /(?<issue>\d+)/)
+    @link_reference_pattern ||= super("issues", /(?<issue>\d+)/)
   end
 
   def to_reference(from_project = nil)
diff --git a/app/models/label.rb b/app/models/label.rb
index 500d5a355217b9ab39655727456825d85bc5dc8e..55c01cae76261939656170c600f719702f65b101 100644
--- a/app/models/label.rb
+++ b/app/models/label.rb
@@ -56,7 +56,7 @@ class Label < ActiveRecord::Base
   # This pattern supports cross-project references.
   #
   def self.reference_pattern
-    %r{
+    @reference_pattern ||= %r{
       (#{Project.reference_pattern})?
       #{Regexp.escape(reference_prefix)}
       (?:
diff --git a/app/models/merge_request.rb b/app/models/merge_request.rb
index 1245cc16d6ada0659d731bef5884eca735e2d946..45c3b0a3a6671edcad113348dab3b38d302ca038 100644
--- a/app/models/merge_request.rb
+++ b/app/models/merge_request.rb
@@ -149,14 +149,14 @@ class MergeRequest < ActiveRecord::Base
   #
   # This pattern supports cross-project references.
   def self.reference_pattern
-    %r{
+    @reference_pattern ||= %r{
       (#{Project.reference_pattern})?
       #{Regexp.escape(reference_prefix)}(?<merge_request>\d+)
     }x
   end
 
   def self.link_reference_pattern
-    super("merge_requests", /(?<merge_request>\d+)/)
+    @link_reference_pattern ||= super("merge_requests", /(?<merge_request>\d+)/)
   end
 
   # Returns all the merge requests from an ActiveRecord:Relation.
diff --git a/app/models/milestone.rb b/app/models/milestone.rb
index bbd59eab9aecea74c0cb0875fe97bc0fd877c81b..07196c0fca447d193fb3364b33940ac31f32309c 100644
--- a/app/models/milestone.rb
+++ b/app/models/milestone.rb
@@ -79,7 +79,7 @@ class Milestone < ActiveRecord::Base
   end
 
   def self.link_reference_pattern
-    super("milestones", /(?<milestone>\d+)/)
+    @link_reference_pattern ||= super("milestones", /(?<milestone>\d+)/)
   end
 
   def self.upcoming
diff --git a/app/models/snippet.rb b/app/models/snippet.rb
index b9e835a448625115b5ee12201c15a7413783e9dd..b96e39372813baa28c1d68bebb872a14db99791d 100644
--- a/app/models/snippet.rb
+++ b/app/models/snippet.rb
@@ -56,14 +56,14 @@ class Snippet < ActiveRecord::Base
   #
   # This pattern supports cross-project references.
   def self.reference_pattern
-    %r{
+    @reference_pattern ||= %r{
       (#{Project.reference_pattern})?
       #{Regexp.escape(reference_prefix)}(?<snippet>\d+)
     }x
   end
 
   def self.link_reference_pattern
-    super("snippets", /(?<snippet>\d+)/)
+    @link_reference_pattern ||= super("snippets", /(?<snippet>\d+)/)
   end
 
   def to_reference(from_project = nil)