diff --git a/Documentation/Makefile b/Documentation/Makefile
index 12f83a11936..3a691eb7419 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    ?= -j auto -W -A nuttx_versions="latest,${NUTTX_VERSIONS}"
+SPHINXOPTS    ?= -j 1 -W -A nuttx_versions="latest,${NUTTX_VERSIONS}"
 SPHINXBUILD   ?= sphinx-build
 SOURCEDIR     = .
 BUILDDIR      = _build