diff --git a/performa/scenarios/mq/omsimulator-ha-call.yaml b/performa/scenarios/mq/omsimulator-ha-call.yaml
index f62f255..315f879 100644
--- a/performa/scenarios/mq/omsimulator-ha-call.yaml
+++ b/performa/scenarios/mq/omsimulator-ha-call.yaml
@@ -38,6 +38,7 @@ execution:
         mode: call
         duration: 100
         threads: 1
+        host_count: 1
         url: {{ rabbit_url }}
 
 report:
diff --git a/performa/scenarios/mq/omsimulator-ha-cast.yaml b/performa/scenarios/mq/omsimulator-ha-cast.yaml
index 215ff3f..f41f269 100644
--- a/performa/scenarios/mq/omsimulator-ha-cast.yaml
+++ b/performa/scenarios/mq/omsimulator-ha-cast.yaml
@@ -38,6 +38,7 @@ execution:
         mode: cast
         duration: 100
         threads: 1
+        host_count: 1
         url: {{ rabbit_url }}
 
 report: