diff --git a/repos/os/src/server/nitpicker/session_component.h b/repos/os/src/server/nitpicker/session_component.h
index a345cba4d..63997034a 100644
--- a/repos/os/src/server/nitpicker/session_component.h
+++ b/repos/os/src/server/nitpicker/session_component.h
@@ -265,7 +265,7 @@ class Nitpicker::Session_component : public  Rpc_object<Session>,
 
 		bool uses_alpha() const override { return _texture && _uses_alpha; }
 
-		unsigned layer() const override { return _domain ? _domain->layer() : ~0UL; }
+		unsigned layer() const override { return _domain ? _domain->layer() : ~0U; }
 
 		bool origin_pointer() const override { return _domain && _domain->origin_pointer(); }