diff --git a/src/NimBLEScan.cpp b/src/NimBLEScan.cpp
index eb87df8..378f66b 100644
--- a/src/NimBLEScan.cpp
+++ b/src/NimBLEScan.cpp
@@ -34,7 +34,7 @@ NimBLEScan::NimBLEScan() {
     m_scan_params.itvl               = 0; // This is defined as the time interval from when the Controller started its last LE scan until it begins the subsequent LE scan. (units=0.625 msec)
     m_scan_params.window             = 0; // The duration of the LE scan. LE_Scan_Window shall be less than or equal to LE_Scan_Interval (units=0.625 msec)
     m_scan_params.limited            = 0; // If set, only discover devices in limited discoverable mode.
-    m_scan_params.filter_duplicates  = 0; // If set, the controller ignores all but the first advertisement from each device.
+    m_scan_params.filter_duplicates  = 1; // If set, the controller ignores all but the first advertisement from each device.
     m_pAdvertisedDeviceCallbacks     = nullptr;
     m_ignoreResults                  = false;
     m_pTaskData                      = nullptr;
@@ -134,6 +134,10 @@ NimBLEScan::~NimBLEScan() {
                                          event_type == BLE_HCI_ADV_RPT_EVTYPE_SCAN_RSP));
 
             if (pScan->m_pAdvertisedDeviceCallbacks) {
+                if (pScan->m_scan_params.filter_duplicates && advertisedDevice->m_callbackSent) {
+                    return 0;
+                }
+
                 // If not active scanning or scan response is not available
                 // or extended advertisement scanning, report the result to the callback now.
                 if(pScan->m_scan_params.passive || !isLegacyAdv ||