diff --git a/doc_theme/templates/layout.html b/doc_theme/templates/layout.html
index 034740369ed10a748856e2205d3315f51a7de62f..5a12a0139435eeb52c6df3349865dc977a8f2f3d 100644
--- a/doc_theme/templates/layout.html
+++ b/doc_theme/templates/layout.html
@@ -168,7 +168,8 @@
             VERSION:'{{ release|e }}',
             COLLAPSE_INDEX:false,
             FILE_SUFFIX:'{{ '' if no_search_suffix else file_suffix }}',
-            HAS_SOURCE:  {{ has_source|lower }}
+            HAS_SOURCE:  {{ has_source|lower }},
+            SOURCELINK_SUFFIX: ".txt",
         };
     </script>
     {%- for scriptfile in script_files %}