diff --git a/docs/CommandGuide/llvmc.pod b/docs/CommandGuide/llvmc.pod
index 86a721a6c43..e3031e123d3 100644
--- a/docs/CommandGuide/llvmc.pod
+++ b/docs/CommandGuide/llvmc.pod
@@ -73,8 +73,9 @@ default behaviour.
 
 =item B<--temp-dir> I<directory>
 
-Write temporary files to the specified directory. This option overrides
-I<--save-temps>.
+Store temporary files in the given directory. This directory is deleted on exit
+unless I<--save-temps> is specified. If I<--save-temps=obj> is also specified,
+I<--temp-dir> is given the precedence.
 
 =item B<--help>
 
diff --git a/tools/llvmc/doc/LLVMC-Reference.rst b/tools/llvmc/doc/LLVMC-Reference.rst
index a5c6fc9f061..3014a3afbff 100644
--- a/tools/llvmc/doc/LLVMC-Reference.rst
+++ b/tools/llvmc/doc/LLVMC-Reference.rst
@@ -97,8 +97,10 @@ configuration libraries:
   the ``-o`` option. The ``--save-temps=cwd`` and ``--save-temps`` switches are
   both synonyms for the default behaviour.
 
-* ``--temp-dir`` - Write temporary files to the specified directory. This option
-  overrides ``--save-temps``.
+* ``--temp-dir DIRECTORY`` - Store temporary files in the given directory. This
+  directory is deleted on exit unless ``--save-temps`` is specified. If
+  ``--save-temps=obj`` is also specified, ``--temp-dir`` is given the
+  precedence.
 
 * ``--check-graph`` - Check the compilation for common errors like mismatched
   output/input language names, multiple default edges and cycles. Because of