diff --git a/sysmocom/scenarios/mod-enb-args@.conf b/sysmocom/scenarios/mod-enb-args@.conf
index a758d01..3e09a99 100644
--- a/sysmocom/scenarios/mod-enb-args@.conf
+++ b/sysmocom/scenarios/mod-enb-args@.conf
@@ -1,3 +1,4 @@
 modifiers:
   enb:
-  - additional_args: ${param1}
+  - additional_args:
+    - ${param1}
diff --git a/sysmocom/scenarios/mod-modem-args@.conf b/sysmocom/scenarios/mod-modem-args@.conf
index dde7796..2ec0834 100644
--- a/sysmocom/scenarios/mod-modem-args@.conf
+++ b/sysmocom/scenarios/mod-modem-args@.conf
@@ -1,3 +1,4 @@
 modifiers:
   modem:
-  - additional_args: ${param1}
+  - additional_args:
+    - ${param1}