diff --git a/sources/Android/android-communications/library/src/main/java/com/polar/androidcommunications/api/ble/model/gatt/BleGattBase.java b/sources/Android/android-communications/library/src/main/java/com/polar/androidcommunications/api/ble/model/gatt/BleGattBase.java
index b7b60991..2d7ae0a4 100755
--- a/sources/Android/android-communications/library/src/main/java/com/polar/androidcommunications/api/ble/model/gatt/BleGattBase.java
+++ b/sources/Android/android-communications/library/src/main/java/com/polar/androidcommunications/api/ble/model/gatt/BleGattBase.java
@@ -303,7 +303,9 @@ protected void addCharacteristic(final UUID characteristic, int properties) {
         if ((properties & PROPERTY_READ) != 0 && !containsCharacteristicRead(characteristic)) {
             characteristicsRead.put(characteristic, true);
         }
-        characteristics.putIfAbsent(characteristic, true);
+        if (!characteristics.containsKey(characteristic)) {
+            characteristics.put(characteristic, true);
+        }
     }
 
     protected void addAvailableCharacteristic(UUID chr, int property) {