diff --git a/bundles/org.openhab.binding.bluetooth.airthings/src/main/java/org/openhab/binding/bluetooth/airthings/internal/AirthingsWaveGen1Handler.java b/bundles/org.openhab.binding.bluetooth.airthings/src/main/java/org/openhab/binding/bluetooth/airthings/internal/AirthingsWaveGen1Handler.java
index 1c98466b18024..7d4051170a307 100644
--- a/bundles/org.openhab.binding.bluetooth.airthings/src/main/java/org/openhab/binding/bluetooth/airthings/internal/AirthingsWaveGen1Handler.java
+++ b/bundles/org.openhab.binding.bluetooth.airthings/src/main/java/org/openhab/binding/bluetooth/airthings/internal/AirthingsWaveGen1Handler.java
@@ -102,7 +102,7 @@ protected void updateChannels(int[] is) {
                     break;
             }
         } else {
-            logger.debug("Illegal data structure length '%d'", String.valueOf(rawdata).length());
+            logger.debug("Illegal data structure length '{}'", String.valueOf(rawdata).length());
         }
     }