diff --git a/clang/docs/LanguageExtensions.rst b/clang/docs/LanguageExtensions.rst
index 7b23e4d1c2f30..40ff2d074e164 100644
--- a/clang/docs/LanguageExtensions.rst
+++ b/clang/docs/LanguageExtensions.rst
@@ -1640,7 +1640,8 @@ The following type trait primitives are supported by Clang. Those traits marked
   were made trivially relocatable via the ``clang::trivial_abi`` attribute.
 * ``__is_trivially_equality_comparable`` (Clang): Returns true if comparing two
   objects of the provided type is known to be equivalent to comparing their
-  value representations.
+  object representations. Note that types containing padding bytes are never
+  trivially equality comparable.
 * ``__is_unbounded_array`` (C++, GNU, Microsoft, Embarcadero)
 * ``__is_union`` (C++, GNU, Microsoft, Embarcadero)
 * ``__is_unsigned`` (C++, Embarcadero):