diff --git a/var/spack/repos/builtin/packages/pythia8/package.py b/var/spack/repos/builtin/packages/pythia8/package.py
index 22cbb2c9490..9c4ca7c3a8e 100644
--- a/var/spack/repos/builtin/packages/pythia8/package.py
+++ b/var/spack/repos/builtin/packages/pythia8/package.py
@@ -179,7 +179,9 @@ def configure_args(self):
             args.append("--with-yoda=" + self.spec["yoda"].prefix)
 
         args += self.with_or_without("python", activation_value="prefix")
-        args += self.with_or_without("openmp", activation_value="prefix", variant="openmpi")
+        args += self.with_or_without(
+            "openmp", activation_value=lambda x: self.spec["openmpi"].prefix, variant="openmpi"
+        )
         args += self.with_or_without("mpich", activation_value="prefix")
         args += self.with_or_without("hdf5", activation_value="prefix")