diff --git a/src/demoreader.cpp b/src/demoreader.cpp
--- a/src/demoreader.cpp
+++ b/src/demoreader.cpp
@@ -25,8 +25,9 @@
 #define M_PI 3.14159265358979323846
 #endif
 
-DemoReader::DemoReader(QIODevice* device, ChannelManager* channelMan, QObject *parent) :
-    AbstractReader(device, channelMan, parent)
+DemoReader::DemoReader(QIODevice* device, ChannelManager* channelMan,
+                       DataRecorder* recorder, QObject* parent) :
+    AbstractReader(device, channelMan, recorder, parent)
 {
     paused = false;
     _numOfChannels = 1;