diff --git a/passes/cmds/portarcs.cc b/passes/cmds/portarcs.cc
index 7a1d5497c..a6ed75de3 100644
--- a/passes/cmds/portarcs.cc
+++ b/passes/cmds/portarcs.cc
@@ -192,16 +192,18 @@ struct PortarcsPass : Pass {
 				if (annotations.count(bit)) {
 					// consistency check
 					log_assert(annotations.at(bit)[0] == ((int) (intptr_t) bit.wire));
-
-					recycling.push_back(annotations.at(ordering[i]));
+				} else {
+					alloc_for_bit(bit);
 				}
+
+				recycling.push_back(annotations.at(ordering[i]));
 			}
 			log_debug("Allocated %lux%d\n", allocated.size(), inputs.size());
 
 			for (auto bit : outputs) {
 				int *p = annotations.at(canonical_bit(bit));
 				for (int i = 0; i < inputs.size(); i++)
-					p[i] = 0;
+					p[i] = -1;
 			}
 
 			for (int i = 0; i < ordering.size(); i++) {