diff --git a/doc/common/glossary.rst b/doc/common/glossary.rst
index 06f76105f8..b87ec81ba1 100644
--- a/doc/common/glossary.rst
+++ b/doc/common/glossary.rst
@@ -4097,7 +4097,7 @@ X
 
 .. glossary::
 
-  X.509
+   X.509
 
       X.509 is the most widely used standard for defining digital
       certificates. It is a data structure that contains the subject