diff --git a/var/spack/repos/builtin/packages/mapl/package.py b/var/spack/repos/builtin/packages/mapl/package.py
index bb9941f43d2..831fcb67500 100644
--- a/var/spack/repos/builtin/packages/mapl/package.py
+++ b/var/spack/repos/builtin/packages/mapl/package.py
@@ -383,6 +383,7 @@ def cmake_args(self):
         # - MVAPICH --> mvapich
         # - HPE MPT --> mpt
         # - Cray MPICH --> mpich
+        # - HPC-X --> openmpi
 
         if self.spec.satisfies("^mpich"):
             args.append(self.define("MPI_STACK", "mpich"))
@@ -398,6 +399,8 @@ def cmake_args(self):
             args.append(self.define("MPI_STACK", "mpt"))
         elif self.spec.satisfies("^cray-mpich"):
             args.append(self.define("MPI_STACK", "mpich"))
+        elif self.spec.satisfies("^hpcx-mpi"):
+            args.append(self.define("MPI_STACK", "openmpi"))
         else:
             raise InstallError("Unsupported MPI stack")