diff --git a/CHANGELOG b/CHANGELOG
index 822fa4be56586b53086a9e939f20bac7436960fd..b07b7da3300dc90052b50cef418b205ea57b2799 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -36,6 +36,7 @@ v 8.8.0 (unreleased)
 
 v 8.7.4
   - Fix always showing build notification message when switching between merge requests
+  - Fix links on wiki pages for relative url setups. !4026 (Artem Sidorenko)
 
 v 8.7.3
   - Emails, Gitlab::Email::Message, Gitlab::Diff, and Premailer::Adapter::Nokogiri are now instrumented
diff --git a/app/models/project_wiki.rb b/app/models/project_wiki.rb
index 7c1a61bb0bfcb99a8df8ae2751b7aced85da5f11..c91cb70ae250773059218ebbeebb6d8968125be9 100644
--- a/app/models/project_wiki.rb
+++ b/app/models/project_wiki.rb
@@ -40,7 +40,7 @@ def http_url_to_repo
   end
 
   def wiki_base_path
-    ["/", @project.path_with_namespace, "/wikis"].join('')
+    [Gitlab.config.gitlab.url, "/", @project.path_with_namespace, "/wikis"].join('')
   end
 
   # Returns the Gollum::Wiki object.
diff --git a/lib/gitlab/url_builder.rb b/lib/gitlab/url_builder.rb
index 2bbbd3074e86f7fbe3bc9160ea175468391c9f89..67a09d5abf585ae61b337a4ec67083606571fa87 100644
--- a/lib/gitlab/url_builder.rb
+++ b/lib/gitlab/url_builder.rb
@@ -62,7 +62,7 @@ def note_url
     end
 
     def wiki_page_url
-      "#{Gitlab.config.gitlab.url}#{object.wiki.wiki_base_path}/#{object.slug}"
+      "#{object.wiki.wiki_base_path}/#{object.slug}"
     end
   end
 end
diff --git a/spec/lib/gitlab/url_builder_spec.rb b/spec/lib/gitlab/url_builder_spec.rb
index bf11472407a89d9d41b891a2586c8ea1e65281ae..c8d3bc0139505903e8150e00ef11ce7e5116aa05 100644
--- a/spec/lib/gitlab/url_builder_spec.rb
+++ b/spec/lib/gitlab/url_builder_spec.rb
@@ -112,7 +112,7 @@
         wiki_page = build(:wiki_page)
         url = described_class.build(wiki_page)
 
-        expect(url).to eq "#{Gitlab.config.gitlab.url}#{wiki_page.wiki.wiki_base_path}/#{wiki_page.slug}"
+        expect(url).to eq "#{Gitlab.config.gitlab.url}/#{wiki_page.wiki.project.path_with_namespace}/wikis/#{wiki_page.slug}"
       end
     end
   end
diff --git a/spec/models/project_wiki_spec.rb b/spec/models/project_wiki_spec.rb
index 532e3f013fd0aa692d77e84ba88c37d753c757f6..ea659f417f2f07df400670f8e3b49978f640c5be 100644
--- a/spec/models/project_wiki_spec.rb
+++ b/spec/models/project_wiki_spec.rb
@@ -38,7 +38,9 @@
 
   describe "#wiki_base_path" do
     it "returns the wiki base path" do
-      wiki_base_path = "/#{project.path_with_namespace}/wikis"
+      gitlab_url = Gitlab.config.gitlab.url
+      wiki_base_path = "#{gitlab_url}/#{project.path_with_namespace}/wikis"
+
       expect(subject.wiki_base_path).to eq(wiki_base_path)
     end
   end