diff --git a/ocaml-rpm-macros.changes b/ocaml-rpm-macros.changes
index e50ca5e..a2e647c 100644
--- a/ocaml-rpm-macros.changes
+++ b/ocaml-rpm-macros.changes
@@ -12,6 +12,7 @@ Fri Nov  1 12:34:56 UTC 2019 - ohering@suse.de
 - Print potential BuildRequires during build
 - Package sml for camlp5
 - SLE_12 has still no license macro, package as doc instead
+- Use _smp_mflags instead of nproc for parallel build
 
 -------------------------------------------------------------------
 Wed Oct  9 05:48:16 UTC 2019 - ohering@suse.de
diff --git a/ocaml-rpm-macros.spec b/ocaml-rpm-macros.spec
index 7e2e2c2..0bedcfc 100644
--- a/ocaml-rpm-macros.spec
+++ b/ocaml-rpm-macros.spec
@@ -314,6 +314,7 @@ ocaml setup.ml -configure \\\
 	dune build \\\
 		--verbose \\\
 		${dune_for_release} \\\
+		%%{?_smp_mflags} \\\
 		'@install' \\\
 		$OCAML_DUNE_BUILD_INSTALL_ARGS
 %%ocaml_dune_install \
@@ -329,6 +330,7 @@ ocaml setup.ml -configure \\\
 	dune install \\\
 		--verbose \\\
 		${dune_for_release} \\\
+		%%{?_smp_mflags} \\\
 		--prefix=%%{_prefix} \\\
 		--libdir=$(ocamlc -where) \\\
 		--destdir=%%{buildroot} \\\
@@ -352,6 +354,7 @@ ocaml setup.ml -configure \\\
 	if dune runtest \\\
 		--verbose \\\
 		${dune_for_release} \\\
+		%%{?_smp_mflags} \\\
 		$OCAML_DUNE_RUNTEST_ARGS ; \
 	then \
 		echo "dune runtest succeeded" ; \