diff --git a/Documentation/Makefile b/Documentation/Makefile
index 77f9b941307..7d19f170e61 100644
--- a/Documentation/Makefile
+++ b/Documentation/Makefile
@@ -23,7 +23,7 @@
 
 # You can set these variables from the command line, and also
 # from the environment for the first two.
-SPHINXOPTS    ?=
+SPHINXOPTS    ?= -j auto
 SPHINXBUILD   ?= sphinx-build
 SOURCEDIR     = .
 BUILDDIR      = _build