diff --git a/src/mem/ruby/network/garnet2.0/SwitchAllocator.cc b/src/mem/ruby/network/garnet2.0/SwitchAllocator.cc
index 144f208..3241343 100644
--- a/src/mem/ruby/network/garnet2.0/SwitchAllocator.cc
+++ b/src/mem/ruby/network/garnet2.0/SwitchAllocator.cc
@@ -350,6 +350,10 @@
 {
     Tick nextCycle = m_router->clockEdge(Cycles(1));
 
+    if (m_router->alreadyScheduled(nextCycle)) {
+        return;
+    }
+
     for (int i = 0; i < m_num_inports; i++) {
         for (int j = 0; j < m_num_vcs; j++) {
             if (m_router->getInputUnit(i)->need_stage(j, SA_, nextCycle)) {