diff --git a/openfpga/src/annotation/route_clock_rr_graph.cpp b/openfpga/src/annotation/route_clock_rr_graph.cpp
index 9fe0a4ad6..06d9c1d5a 100644
--- a/openfpga/src/annotation/route_clock_rr_graph.cpp
+++ b/openfpga/src/annotation/route_clock_rr_graph.cpp
@@ -149,7 +149,7 @@ static int route_clock_tree_rr_graph(
         VTR_ASSERT(rr_graph.valid_node(des_node));
         /* Internal drivers may appear at the switch point. Check if there are any defined and related rr_node found as incoming edges. If the global net is mapped to the internal driver, use it as the previous node  */
         size_t use_int_driver = 0;
-        for (!spine_switch_point_internal_drivers(ispine, switch_point_id).empty() && tree2clk_pin_map.find(ipin) != tree2clk_pin_map.end()) {
+        if (!clk_ntwk.spine_switch_point_internal_drivers(ispine, switch_point_id).empty() && tree2clk_pin_map.find(ipin) != tree2clk_pin_map.end()) {
           for (RREdgeId cand_edge : rr_graph.node_in_edges(des_node)) {
             RRNodeId opin_node = rr_graph.edge_src_node(cand_edge);
             if (OPIN != rr_graph.node_type(opin_node)) {