diff --git a/features/FEATURE_BLE/source/gap/AdvertisingDataBuilder.cpp b/features/FEATURE_BLE/source/gap/AdvertisingDataBuilder.cpp
index 0764688e83a..14aee492b1e 100644
--- a/features/FEATURE_BLE/source/gap/AdvertisingDataBuilder.cpp
+++ b/features/FEATURE_BLE/source/gap/AdvertisingDataBuilder.cpp
@@ -256,7 +256,7 @@ ble_error_t AdvertisingDataBuilder::setServiceData(
     );
 
     /* if we can't fit the new data do not proceed */
-    if (total_size > data.size() - (_payload_length - old_size)) {
+    if (total_size > (_buffer.size() - (_payload_length - old_size))) {
         return BLE_ERROR_BUFFER_OVERFLOW;
     }