diff --git a/var/spack/repos/builtin/packages/openmc/package.py b/var/spack/repos/builtin/packages/openmc/package.py
index e6d32767fd..aed4f4b0e9 100644
--- a/var/spack/repos/builtin/packages/openmc/package.py
+++ b/var/spack/repos/builtin/packages/openmc/package.py
@@ -42,6 +42,8 @@ class Openmc(MakefilePackage):
 
     build_directory = 'src'
 
+    parallel = False
+
     @property
     def build_targets(self):