diff --git a/common/route/router2.cc b/common/route/router2.cc
index fbc59772..3d7ca2f8 100644
--- a/common/route/router2.cc
+++ b/common/route/router2.cc
@@ -611,6 +611,8 @@ struct Router2
                 auto &wd = wire_data(cursor);
                 if (ctx->debug)
                     log("      %s (driver output)\n", ctx->nameOfWire(cursor));
+                if (wd.reserved_net == PerWireData::RESERVED_UNAVAILABLE)
+                    break;
                 did_something |= (wd.reserved_net != net->udata);
                 if (wd.reserved_net != -1 && wd.reserved_net != net->udata)
                     log_error("attempting to reserve driver output path wire '%s' for nets '%s' and '%s'\n",