diff --git a/Generators/GeneratorFilters/src/TTbarWToLeptonFilter.cxx b/Generators/GeneratorFilters/src/TTbarWToLeptonFilter.cxx
index f6f239067e27fb824da0612fc007e2672305c1de..391b41d0fedcc504c36f70c4f31b695e46a9f21e 100644
--- a/Generators/GeneratorFilters/src/TTbarWToLeptonFilter.cxx
+++ b/Generators/GeneratorFilters/src/TTbarWToLeptonFilter.cxx
@@ -156,6 +156,7 @@ StatusCode TTbarWToLeptonFilter::filterEvent() {
       HepMC::GenParticle * grandchild_mcpart = (*grandchild_mcpartItr);
 		  int grandchild_pid = grandchild_mcpart->pdg_id();
 
+                  // cppcheck-suppress shiftNegative; false positive!
 		  ATH_MSG_DEBUG("W (t/tbar) has " << mcpart_n_particles_out << " children and the pdg_id of the next is " << grandchild_pid);
 
 		  // Check if the W's child is W again. If yes, then move to its next decay vertex in a decay tree