diff --git a/src/coap.h b/src/coap.h
index c2fcd40..d2ed7cb 100644
--- a/src/coap.h
+++ b/src/coap.h
@@ -31,6 +31,7 @@ namespace CoAPMessageType {
     DESCRIBE,
     FUNCTION_CALL,
     VARIABLE_REQUEST,
+    SAVE_BEGIN,
     UPDATE_BEGIN,
     UPDATE_DONE,
     CHUNK,
diff --git a/src/spark_protocol.cpp b/src/spark_protocol.cpp
index 08ae3fc..48e7a87 100644
--- a/src/spark_protocol.cpp
+++ b/src/spark_protocol.cpp
@@ -71,6 +71,7 @@ void SparkProtocol::init(const char *id,
 
   callback_send = callbacks.send;
   callback_receive = callbacks.receive;
+  callback_prepare_to_save_file = callbacks.prepare_to_save_file;
   callback_prepare_for_firmware_update = callbacks.prepare_for_firmware_update;
   callback_finish_firmware_update = callbacks.finish_firmware_update;
   callback_calculate_crc = callbacks.calculate_crc;
@@ -290,6 +291,7 @@ CoAPMessageType::Enum
           return CoAPMessageType::EVENT;
         case 'h': return CoAPMessageType::HELLO;
         case 'f': return CoAPMessageType::FUNCTION_CALL;
+        case 's': return CoAPMessageType::SAVE_BEGIN;
         case 'u': return CoAPMessageType::UPDATE_BEGIN;
         case 'c': return CoAPMessageType::CHUNK;
         default: break;
@@ -1002,6 +1004,8 @@ bool SparkProtocol::handle_received_message(void)
       }
       break;
     }
+    case CoAPMessageType::SAVE_BEGIN:
+      // fall through
     case CoAPMessageType::UPDATE_BEGIN:
       // send ACK
       *msg_to_send = 0;
@@ -1013,7 +1017,19 @@ bool SparkProtocol::handle_received_message(void)
         return false;
       }
 
-      callback_prepare_for_firmware_update();
+      if(message_type == CoAPMessageType::SAVE_BEGIN)
+      {
+        // save file to the specified location in external flash
+        unsigned int sflash_address = queue[8] << 24 | queue[9] << 16 | queue[10] << 8 | queue[11];
+        // file size information is required to calculate the sectors that need to be erased
+        unsigned int file_size = queue[12] << 24 | queue[13] << 16 | queue[14] << 8 | queue[15];
+        callback_prepare_to_save_file(sflash_address, file_size);
+      }
+      else
+      {
+        callback_prepare_for_firmware_update();
+      }
+
       last_chunk_millis = callback_millis();
       chunk_index = 0;
       updating = true;
diff --git a/src/spark_protocol.h b/src/spark_protocol.h
index 39abce0..3179622 100644
--- a/src/spark_protocol.h
+++ b/src/spark_protocol.h
@@ -62,6 +62,7 @@ struct SparkCallbacks
 {
   int (*send)(const unsigned char *buf, int buflen);
   int (*receive)(unsigned char *buf, int buflen);
+  void (*prepare_to_save_file)(unsigned int sflash_address, unsigned int file_size);
   void (*prepare_for_firmware_update)(void);
   void (*finish_firmware_update)(void);
   long unsigned int (*calculate_crc)(unsigned char *buf, long unsigned int buflen);
@@ -146,6 +147,7 @@ class SparkProtocol
 
     int (*callback_send)(const unsigned char *buf, int buflen);
     int (*callback_receive)(unsigned char *buf, int buflen);
+    void (*callback_prepare_to_save_file)(unsigned int sflash_address, unsigned int file_size);
     void (*callback_prepare_for_firmware_update)(void);
     void (*callback_finish_firmware_update)(void);
     long unsigned int (*callback_calculate_crc)(unsigned char *buf, long unsigned int buflen);