diff --git a/CHANGES b/CHANGES
index 41d512023..26849effa 100644
--- a/CHANGES
+++ b/CHANGES
@@ -25,6 +25,8 @@ Incompatible changes
 * #2557: autodoc: :confval:`autodoc_mock_imports` only mocks specified modules
   with their descendants.  It does not mock their ancestors.  If you want to
   mock them, please specify the name of ancestors implicitly.
+* #3620: html theme: move DOCUMENTATION_OPTIONS to independent JavaScript file
+  (refs: #4295)
 
 Deprecated
 ----------
diff --git a/sphinx/themes/basic/documentation_options.js_t b/sphinx/themes/basic/documentation_options.js_t
new file mode 100644
index 000000000..e76f55a4e
--- /dev/null
+++ b/sphinx/themes/basic/documentation_options.js_t
@@ -0,0 +1,9 @@
+var DOCUMENTATION_OPTIONS = {
+    URL_ROOT: '{{ url_root }}',
+    VERSION: '{{ release|e }}',
+    LANGUAGE: '{{ language }}',
+    COLLAPSE_INDEX: false,
+    FILE_SUFFIX: '{{ '' if no_search_suffix else file_suffix }}',
+    HAS_SOURCE: {{ has_source|lower }},
+    SOURCELINK_SUFFIX: '{{ sourcelink_suffix }}'
+};
diff --git a/sphinx/themes/basic/layout.html b/sphinx/themes/basic/layout.html
index 050de15df..dc05e980d 100644
--- a/sphinx/themes/basic/layout.html
+++ b/sphinx/themes/basic/layout.html
@@ -87,17 +87,7 @@
 {%- endmacro %}
 
 {%- macro script() %}
-    <script type="text/javascript">
-      var DOCUMENTATION_OPTIONS = {
-        URL_ROOT:    '{{ url_root }}',
-        VERSION:     '{{ release|e }}',
-        LANGUAGE:    '{{ language }}',
-        COLLAPSE_INDEX: false,
-        FILE_SUFFIX: '{{ '' if no_search_suffix else file_suffix }}',
-        HAS_SOURCE:  {{ has_source|lower }},
-        SOURCELINK_SUFFIX: '{{ sourcelink_suffix }}'
-      };
-    </script>
+    <script type="text/javascript" src="{{ pathto('_static/documentation_options.js', 1) }}"></script>
     {%- for scriptfile in script_files %}
     <script type="text/javascript" src="{{ pathto(scriptfile, 1) }}"></script>
     {%- endfor %}