I cannot implement Hit and Sensitive Detector classes

Hello everyone! I am currently modifying the basic example B1 to score the information not by the Stepping/Event/Run Action but with a sensitive detector that would have several volumes assigned to it. I manually created “B1Hit.hh” and “B1SensitiveDetector.hh” header files, but when the file “B1SensitiveDetector.hh” is called, I get the following error:

error: unknown type name ‘HitsCollection’ HitsCollection *hitsCollection;

HitsCollection is an alias that I created through a typedef in the “B1hit.hh” file:

typedef G4THitsCollection HitsColleсtion;

I even tried to define the path to the “B1Hit.hh” header file explicitly, however, with no results…

Would you please be able to give me a hint on how to get round this issue?
Thank you in advance!

PS: please, find attached my files “B1Hit.hh” and “B1SensitiveDetector.hh”.
B1Hit.hh (492 Bytes)
B1SensitiveDetector.hh (609 Bytes)