diff --git a/csaxs_bec/device_configs/sastt_aerotech.yaml b/csaxs_bec/device_configs/sastt_aerotech.yaml
index 40adb73f..b7981b79 100644
--- a/csaxs_bec/device_configs/sastt_aerotech.yaml
+++ b/csaxs_bec/device_configs/sastt_aerotech.yaml
@@ -120,11 +120,12 @@ aerocapture:
     port: 8000
     drive_axis: X
     # DATAACQ source -> axis: 0-5 local encoder counter, 6-11 MXR channel 0-5 (max. 4 kHz)
+    # keys are quoted: integer map keys break the config message (msgpack strict_map_key)
     channels:
-      6: X
-      11: Z
-      2: Y
-      9: U
+      "6": X
+      "11": Z
+      "2": Y
+      "9": U
   enabled: false
   onFailure: buffer
   readOnly: false
diff --git a/csaxs_bec/device_configs/sastt_aerotech_panda.yaml b/csaxs_bec/device_configs/sastt_aerotech_panda.yaml
index 039071f8..2bcb4f93 100644
--- a/csaxs_bec/device_configs/sastt_aerotech_panda.yaml
+++ b/csaxs_bec/device_configs/sastt_aerotech_panda.yaml
@@ -110,11 +110,12 @@ aerocapture:
     port: 8000
     drive_axis: X
     # DATAACQ source -> axis: 0-5 local encoder counter, 6-11 MXR channel 0-5 (max. 4 kHz)
+    # keys are quoted: integer map keys break the config message (msgpack strict_map_key)
     channels:
-      6: X
-      11: Z
-      2: Y
-      9: U
+      "6": X
+      "11": Z
+      "2": Y
+      "9": U
   enabled: false
   onFailure: buffer
   readOnly: false
diff --git a/csaxs_bec/device_configs/simulated_omny/simulated_sastt_aerotech.yaml b/csaxs_bec/device_configs/simulated_omny/simulated_sastt_aerotech.yaml
index e95bd902..7e5d4a2e 100644
--- a/csaxs_bec/device_configs/simulated_omny/simulated_sastt_aerotech.yaml
+++ b/csaxs_bec/device_configs/simulated_omny/simulated_sastt_aerotech.yaml
@@ -109,11 +109,12 @@ aerocapture:
     port: 8000
     drive_axis: X
     # DATAACQ source -> axis: 0-5 local encoder counter, 6-11 MXR channel 0-5 (max. 4 kHz)
+    # keys are quoted: integer map keys break the config message (msgpack strict_map_key)
     channels:
-      6: X
-      11: Z
-      2: Y
-      9: U
+      "6": X
+      "11": Z
+      "2": Y
+      "9": U
   enabled: true
   onFailure: buffer
   readOnly: false