diff --git a/doc/reference.rst b/doc/reference.rst
index de35539e..357aec56 100644
--- a/doc/reference.rst
+++ b/doc/reference.rst
@@ -83,6 +83,7 @@ Utilities
    :members:
 
 .. doxygenclass:: fmt::Buffer
+   :protected-members:
    :members:
 
 System Errors