diff --git a/src/fsfw/datalinklayer/MapPacketExtraction.cpp b/src/fsfw/datalinklayer/MapPacketExtraction.cpp
index 839209ac..f2a6c550 100644
--- a/src/fsfw/datalinklayer/MapPacketExtraction.cpp
+++ b/src/fsfw/datalinklayer/MapPacketExtraction.cpp
@@ -89,12 +89,17 @@ ReturnValue_t MapPacketExtraction::unpackBlockingPackets(TcTransferFrame* frame)
   if (totalLength > MAX_PACKET_SIZE) return CONTENT_TOO_LARGE;
   uint8_t* position = frame->getDataField();
   while ((totalLength > ccsds::HEADER_LEN)) {
-    SpacePacketBase packet(position);
-    uint32_t packetSize = packet.getFullSize();
+    SpacePacketReader packet(position, totalLength);
+    status = packet.checkSize();
+    if(status != returnvalue::OK) {
+      // TODO: Better error handling
+      status = DATA_CORRUPTED;
+    }
+    uint32_t packetSize = packet.getFullPacketLen();
     if (packetSize <= totalLength) {
-      status = sendCompletePacket(packet.getWholeData(), packet.getFullSize());
-      totalLength -= packet.getFullSize();
-      position += packet.getFullSize();
+      status = sendCompletePacket(packet.getFullData(), packet.getFullPacketLen());
+      totalLength -= packet.getFullPacketLen();
+      position += packet.getFullPacketLen();
       status = returnvalue::OK;
     } else {
       status = DATA_CORRUPTED;
@@ -107,7 +112,7 @@ ReturnValue_t MapPacketExtraction::unpackBlockingPackets(TcTransferFrame* frame)
   return status;
 }
 
-ReturnValue_t MapPacketExtraction::sendCompletePacket(uint8_t* data, uint32_t size) {
+ReturnValue_t MapPacketExtraction::sendCompletePacket(const uint8_t* data, uint32_t size) {
   store_address_t store_id;
   ReturnValue_t status = this->packetStore->addData(&store_id, data, size);
   if (status == returnvalue::OK) {
diff --git a/src/fsfw/datalinklayer/MapPacketExtraction.h b/src/fsfw/datalinklayer/MapPacketExtraction.h
index fab7f3c3..3aa92aeb 100644
--- a/src/fsfw/datalinklayer/MapPacketExtraction.h
+++ b/src/fsfw/datalinklayer/MapPacketExtraction.h
@@ -47,7 +47,7 @@ class MapPacketExtraction : public MapPacketExtractionIF {
    * @param size	Complete total size of the packet.
    * @return	Return Code of the Packet Store or the Message Queue.
    */
-  ReturnValue_t sendCompletePacket(uint8_t* data, uint32_t size);
+  ReturnValue_t sendCompletePacket(const uint8_t* data, uint32_t size);
   /**
    * Helper method to reset the internal buffer.
    */