diff --git a/Resources/doc/conf.py b/Resources/doc/conf.py
index 7e61a655..c9d29328 100644
--- a/Resources/doc/conf.py
+++ b/Resources/doc/conf.py
@@ -12,9 +12,10 @@
 highlight_language = 'php'
 
 extensions = [
-    'sphinxcontrib.spelling',
-    'sphinx_rtd_theme',
     "sphinx.ext.intersphinx",
+    'sphinx_rtd_theme',
+    'sphinxcontrib.phpdomain',
+    'sphinxcontrib.spelling',
 ]
 
 # Spelling configuration