diff --git a/clang-tools-extra/docs/clang-tidy/checks/misc-unused-alias-decls.rst b/clang-tools-extra/docs/clang-tidy/checks/misc-unused-alias-decls.rst
--- a/clang-tools-extra/docs/clang-tidy/checks/misc-unused-alias-decls.rst
+++ b/clang-tools-extra/docs/clang-tidy/checks/misc-unused-alias-decls.rst
@@ -5,3 +5,10 @@
 
 
 Finds unused namespace alias declarations.
+
+.. code-block:: c++
+
+  namespace my_namespace {
+  class C {};
+  }
+  namespace unused_alias = ::my_namespace;