diff --git a/python-fastavro.spec b/python-fastavro.spec
index c7ed3f6..6363e1c 100644
--- a/python-fastavro.spec
+++ b/python-fastavro.spec
@@ -119,9 +119,11 @@ sed -r -e '/^(black|check-manifest|flake8|mypy|twine)\b/d' \
 %pyproject_wheel
 
 BLIB="${PWD}/build/lib.%{python3_platform}-cpython-%{python3_version_nodots}"
-PYTHONPATH="${BLIB}" %make_build -C docs man SPHINXOPTS='-n %{?_smp_mflags}'
+PYTHONPATH="${BLIB}" %make_build -C docs man \
+    SPHINXOPTS='-n -j%{?_smp_build_ncpus}'
 %if %{with doc_pdf}
-PYTHONPATH="${BLIB}" %make_build -C docs latex SPHINXOPTS='-n %{?_smp_mflags}'
+PYTHONPATH="${BLIB}" %make_build -C docs latex \
+    SPHINXOPTS='-n -j%{?_smp_build_ncpus}'
 %make_build -C docs/_build/latex LATEXMKOPTS='-quiet'
 %endif