diff --git a/float/plugins/inventory/float.py b/float/plugins/inventory/float.py
index 808b52b16b3f898776544a3f8e13d28ed34ca40e..906a7c5eb84f9e90b00134c21c8aa469e518c26c 100644
--- a/float/plugins/inventory/float.py
+++ b/float/plugins/inventory/float.py
@@ -499,6 +499,8 @@ class Assignments(object):
             scheduling_groups = service['scheduling_groups']
         available_hosts = set()
         for g in scheduling_groups:
+            if g not in group_map:
+                raise Exception(f'The scheduling_group "{g}" is not defined in inventoy')
             available_hosts.update(group_map[g])
         return list(available_hosts)