diff --git a/prometheus/map.jinja b/prometheus/map.jinja
index c9aadce..3ff6bb6 100644
--- a/prometheus/map.jinja
+++ b/prometheus/map.jinja
@@ -1,5 +1,9 @@
 {% set server = salt['grains.filter_by']({
+  'default': {
+  },
 }, merge=salt['pillar.get']('prometheus:server')) %}
 
 {% set alertmanager = salt['grains.filter_by']({
+  'default': {
+  },
 }, merge=salt['pillar.get']('prometheus:alertmanager')) %}