diff --git a/var/spack/repos/builtin/packages/xsbench/package.py b/var/spack/repos/builtin/packages/xsbench/package.py
index 3f9831dbf26..da4e7263bef 100644
--- a/var/spack/repos/builtin/packages/xsbench/package.py
+++ b/var/spack/repos/builtin/packages/xsbench/package.py
@@ -46,8 +46,10 @@ def build_targets(self):
 
         if '+mpi' in self.spec:
             targets.append('CC={0}'.format(self.spec['mpi'].mpicc))
+            targets.append('MPI=yes')
         else:
-            targets.append('CC={0}'.format(self.compiler.cxx))
+            targets.append('CC={0}'.format(self.compiler.cc))
+            targets.append('MPI=no')
 
         if '+openmp' in self.spec:
             cflags += ' ' + self.compiler.openmp_flag