diff --git a/docs/Makefile b/docs/Makefile
index 3c8a65d81c..6f77269be2 100644
--- a/docs/Makefile
+++ b/docs/Makefile
@@ -2,7 +2,7 @@
 #
 
 # You can set these variables from the command line.
-SPHINXOPTS    =
+SPHINXOPTS    = -j auto
 SPHINXBUILD   = sphinx-build
 SOURCEDIR     = .
 BUILDDIR      = _build