diff --git a/examples/device/dfu_freertos/src/main.c b/examples/device/dfu_freertos/src/main.c
index 3918a9ead..b4414a793 100644
--- a/examples/device/dfu_freertos/src/main.c
+++ b/examples/device/dfu_freertos/src/main.c
@@ -142,20 +142,48 @@ static void dl_task(void* arg)
           tud_dfu_finish_flashing(DFU_STATUS_ERR_CHECK_ERASED);
           continue;
         }
+        // check if the data is different and we need to write it
         if (0 == memcmp(dl_block, flash_block, dl_block_len)) { // data is the same
+          ESP_LOGD(TAG, "data already flashed");
           dl_block_len = 0; // ready for next block
           tud_dfu_finish_flashing(DFU_STATUS_OK); // flashing op for download complete without error
           continue;
         }
-        if (0 == (dl_block_num * CFG_TUD_DFU_XFER_BUFSIZE) % 4096) { // new page
-          rc = esp_partition_erase_range(ota_part, dl_block_num * CFG_TUD_DFU_XFER_BUFSIZE, 4096); // erase page (block is smaller than page
+        // check if the area to be written is already erased
+        bool erased = true;
+        for (uint16_t i = 0; i < dl_block_len && erased; i++) {
+          if (0xff != flash_block[i]) {
+            erased = false;
+          }
+        }
+        // get range when some of it is not erased
+        if (!erased) {
+#define RANGE_SIZE 4096U // range/page size for the flash
+          // get range data
+          const uint32_t range_start = (dl_block_num * CFG_TUD_DFU_XFER_BUFSIZE) - ((dl_block_num * CFG_TUD_DFU_XFER_BUFSIZE) % RANGE_SIZE);
+          uint8_t range_data[RANGE_SIZE];
+          rc = esp_partition_read(ota_part, range_start, range_data, RANGE_SIZE);
+          if (ESP_OK != rc) {
+            ESP_LOGE(TAG, "reading range failed");
+            tud_dfu_finish_flashing(DFU_STATUS_ERR_CHECK_ERASED);
+            continue;
+          }
+          // erase range
+          rc = esp_partition_erase_range(ota_part, range_start, RANGE_SIZE); // erase page (block is smaller than page)
           if (ESP_OK != rc) {
             ESP_LOGE(TAG, "erase range failed");
             tud_dfu_finish_flashing(DFU_STATUS_ERR_ERASE);
             continue;
           }
+          // write range data before downloaded block
+          rc = esp_partition_write(ota_part, range_start, range_data, dl_block_num * CFG_TUD_DFU_XFER_BUFSIZE - range_start); // write old
+          if (ESP_OK != rc) {
+            ESP_LOGE(TAG, "writing existing range failed");
+            tud_dfu_finish_flashing(DFU_STATUS_ERR_WRITE);
+            continue;
+          }
         }
-        rc = esp_partition_write(ota_part, dl_block_num * CFG_TUD_DFU_XFER_BUFSIZE, flash_block, dl_block_len); // write new data
+        rc = esp_partition_write(ota_part, dl_block_num * CFG_TUD_DFU_XFER_BUFSIZE, dl_block, dl_block_len); // write new data
         if (ESP_OK != rc) {
           ESP_LOGE(TAG, "writing range failed");
           tud_dfu_finish_flashing(DFU_STATUS_ERR_WRITE);
@@ -239,7 +267,7 @@ int main(void)
 #endif
 
   // create task to handle download progress
-  xTaskCreate(dl_task, "dl_task", 2 * 1024, NULL, 8, NULL);
+  xTaskCreate(dl_task, "dl_task", 7 * 1024, NULL, 8, NULL);
 
   ESP_LOGI(TAG, "DFU mode");