diff --git a/Modules/ITS/include/ITS/ITSTrackTask.h b/Modules/ITS/include/ITS/ITSTrackTask.h
index 01fe7fbb12..cc89ea0e1f 100644
--- a/Modules/ITS/include/ITS/ITSTrackTask.h
+++ b/Modules/ITS/include/ITS/ITSTrackTask.h
@@ -226,7 +226,7 @@ class ITSTrackTask : public TaskInterface
     // implementation of the function to be minimized
     double operator()(const double* par)
     { // const double -> double
-      assert(fHits != 0);
+      assert(fHits.size() != 0);
 
       int nhits = fHits.size();
       double sum = 0;