diff --git a/CHANGES b/CHANGES
index bc9dfa335..c91200328 100644
--- a/CHANGES
+++ b/CHANGES
@@ -72,6 +72,7 @@ Bugs fixed
 * #8683: :confval:`html_last_updated_fmt` generates wrong time zone for %Z
 * #1112: ``download`` role creates duplicated copies when relative path is
   specified
+* #8339: make latexpdf fails when using literal-blocks and fancybox package
 
 Testing
 --------
diff --git a/doc/latex.rst b/doc/latex.rst
index 53fe9301a..039c72171 100644
--- a/doc/latex.rst
+++ b/doc/latex.rst
@@ -95,6 +95,12 @@ Keys that you may want to override include:
    A string which will be positioned early in the preamble, designed to
    contain ``\\PassOptionsToPackage{options}{foo}`` commands.
 
+   .. hint::
+
+      It may be also used for loading LaTeX packages very early in the
+      preamble.  For example package ``fancybox`` is incompatible with
+      being loaded via the ``'preamble'`` key, it must be loaded earlier.
+
    Default: ``''``
 
    .. versionadded:: 1.4
diff --git a/sphinx/texinputs/sphinx.sty b/sphinx/texinputs/sphinx.sty
index 4b637a9ec..ed4f56869 100644
--- a/sphinx/texinputs/sphinx.sty
+++ b/sphinx/texinputs/sphinx.sty
@@ -966,9 +966,9 @@
 % - with possibly of a top caption, non-separable by pagebreak.
 % - and usable inside tables or footnotes ("footnotehyper-sphinx").
 
-% For extensions which use \OriginalVerbatim and compatibility with Sphinx <
-% 1.5, we define and use these when (unmodified) Verbatim will be needed. But
-% Sphinx >= 1.5 does not modify the \Verbatim macro anymore.
+% Prior to Sphinx 1.5, \Verbatim and \endVerbatim were modified by Sphinx.
+% The aliases defined here are used in sphinxVerbatim environment and can
+% serve as hook-points with no need to modify \Verbatim itself.
 \let\OriginalVerbatim   \Verbatim
 \let\endOriginalVerbatim\endVerbatim