diff --git a/tree/treeplayer/src/TDFNodes.cxx b/tree/treeplayer/src/TDFNodes.cxx
index 42f4ed33a2d244f88780a5415661e2dae5de3e10..f50487c828f45ea0e32763692d6d7f80ed5a2e6f 100644
--- a/tree/treeplayer/src/TDFNodes.cxx
+++ b/tree/treeplayer/src/TDFNodes.cxx
@@ -231,7 +231,7 @@ void TLoopManager::RunTreeProcessorMT()
       CleanUpTask(slot);
       slotStack.ReturnSlot(slot);
    });
-#endif // not implemented otherwise
+#endif // no-op otherwise (will not be called)
 }
 
 /// Run event loop over one or multiple ROOT files, in sequence.