diff --git a/app/controllers/api_docs_controller.rb b/app/controllers/api_docs_controller.rb
index 703053f05d3b..c8af4c7ed1c1 100644
--- a/app/controllers/api_docs_controller.rb
+++ b/app/controllers/api_docs_controller.rb
@@ -36,5 +36,7 @@ class APIDocsController < ApplicationController
 
   def index
     render_404 unless Setting.apiv3_docs_enabled?
+
+    render locals: { skip_base_tag: true }
   end
 end
diff --git a/app/views/layouts/_common_head.html.erb b/app/views/layouts/_common_head.html.erb
index 632134ff6a33..9235707139cd 100644
--- a/app/views/layouts/_common_head.html.erb
+++ b/app/views/layouts/_common_head.html.erb
@@ -6,7 +6,9 @@
 <% relative_url_root = OpenProject::Configuration["rails_relative_url_root"] || "" %>
 <meta name="app_title" content="<%= page_title(*html_title_parts) %>">
 <meta name="app_base_path" content="<%= relative_url_root %>">
-<base href="<%= relative_url_root %>/">
+<% unless local_assigns[:skip_base_tag] %>
+  <base href="<%= relative_url_root %>/">
+<% end %>
 <% if @project %>
   <meta name="current_project"
         data-project-name="<%= h @project.name %>"
diff --git a/app/views/layouts/base.html.erb b/app/views/layouts/base.html.erb
index 89ea0016d8bb..7998240eb722 100644
--- a/app/views/layouts/base.html.erb
+++ b/app/views/layouts/base.html.erb
@@ -32,7 +32,7 @@ See COPYRIGHT and LICENSE files for more details.
       xml:lang="<%= I18n.locale.to_s %>"
       class="<%= "in_modal" unless show_decoration %>">
 <head>
-  <%= render partial: "layouts/common_head" %>
+  <%= render partial: "layouts/common_head", locals: local_assigns %>
   <!-- project specific tags -->
   <%= call_hook :view_layouts_base_html_head %>
   <!-- page specific tags -->
