diff --git a/python-llvmlite.spec b/python-llvmlite.spec
index c413982..6e058b7 100644
--- a/python-llvmlite.spec
+++ b/python-llvmlite.spec
@@ -120,7 +120,7 @@ export LLVM_CONFIG="%{_libdir}/llvm11/bin/llvm-config"
 %pyproject_wheel
 
 %if %{with doc_pdf}
-%make_build -C docs latex SPHINXOPTS='%{?_smp_mflags}'
+%make_build -C docs latex SPHINXOPTS='-j%{?_smp_build_ncpus}'
 %make_build -C docs/_build/latex LATEXMKOPTS='-quiet'
 %endif