diff --git a/passes/cmds/sta.cc b/passes/cmds/sta.cc
index 1ffc70838..a19ae8184 100644
--- a/passes/cmds/sta.cc
+++ b/passes/cmds/sta.cc
@@ -111,8 +111,11 @@ struct StaWorker
 						if (it == t.arrival.end())
 							continue;
 						const auto &s = it->second.second;
-						if (cell->hasPort(s.name))
-							data[cell->getPort(s.name)[s.offset]].fanouts.emplace_back(bit,it->second.first,s.name);
+						if (cell->hasPort(s.name)) {
+							auto &s_bit = cell->getPort(s.name)[s.offset];
+							if (s_bit.wire)
+								data[s_bit].fanouts.emplace_back(bit,it->second.first,s.name);
+						}
 					}
 				}
 			}