1 files changed, 9 insertions, 0 deletions
diff --git a/sphinx/builders/dirhtml.py b/sphinx/builders/dirhtml.py
index 7ab6fad98..d5d61c273 100644
--- a/sphinx/builders/dirhtml.py
+++ b/sphinx/builders/dirhtml.py
@@ -11,6 +11,7 @@
 from os import path
 
 from sphinx.builders.html import StandaloneHTMLBuilder
+from sphinx.deprecation import RemovedInSphinx40Warning, deprecated_alias
 from sphinx.util import logging
 from sphinx.util.osutil import SEP, os_path
 
@@ -55,6 +56,14 @@ class DirectoryHTMLBuilder(StandaloneHTMLBuilder):
         self.globalcontext['no_search_suffix'] = True
 
 
+# for compatibility
+deprecated_alias('sphinx.builders.html',
+                 {
+                     'DirectoryHTMLBuilder': DirectoryHTMLBuilder,
+                 },
+                 RemovedInSphinx40Warning)
+
+
 def setup(app):
     # type: (Sphinx) -> Dict[str, Any]
     app.setup_extension('sphinx.builders.html')