diff --git a/var/spack/repos/builtin/packages/charm/package.py b/var/spack/repos/builtin/packages/charm/package.py
index 6bbbf0632775832a732c630492a34216f2a9c3a1..b232e97442a279132769dae805fe3d6575788c1f 100644
--- a/var/spack/repos/builtin/packages/charm/package.py
+++ b/var/spack/repos/builtin/packages/charm/package.py
@@ -71,7 +71,7 @@ class Charm(Package):
     # Communication mechanisms (choose exactly one)
     variant(
         "backend",
-        default="mpi",
+        default="netlrts",
         values=("mpi", "multicore", "netlrts", "verbs", "gni",
                 "ofi", "pami", "pamilrts"),
         description="Set the backend to use"