diff --git a/templates/mpi.conf.j2 b/templates/mpi.conf.j2
index 986b62cf..8b19ce0d 100644
--- a/templates/mpi.conf.j2
+++ b/templates/mpi.conf.j2
@@ -1,5 +1,5 @@
 # {{ ansible_managed }}
-{% for k, v in openhpc_mpi_config.items %}
+{% for k, v in openhpc_mpi_config.items() %}
 {%  if v != "omit" %}{# allow removing items using setting key: omit #}
 {{ k }}={{ v | join(',') if (v is sequence and v is not string) else v }}
 {%  endif %}