diff --git a/docs/Makefile b/docs/Makefile
index 05709617c3..766a669a50 100644
--- a/docs/Makefile
+++ b/docs/Makefile
@@ -3,7 +3,7 @@
 
 # You can set these variables from the command line.
 PYTHON        = python3
-SPHINXOPTS    = -W --keep-going
+SPHINXOPTS    = -W --keep-going -j auto
 SPHINXBUILD   = sphinx-build
 PAPER         =
 BUILDDIR      = build/$(MICROPY_PORT)