diff --git a/src/mpl2/src/hier_rtlmp.cpp b/src/mpl2/src/hier_rtlmp.cpp
index 42965e645c5..b339302b167 100644
--- a/src/mpl2/src/hier_rtlmp.cpp
+++ b/src/mpl2/src/hier_rtlmp.cpp
@@ -539,7 +539,10 @@ void HierRTLMP::runMultilevelAutoclustering()
 
   } else {
     multilevelAutocluster(root_cluster_);
-    breakMixedLeafCluster(root_cluster_);
+
+    std::vector<std::vector<Cluster*>> mixed_leaves;
+    fetchMixedLeaves(root_cluster_, mixed_leaves);
+    breakMixedLeaves(mixed_leaves);
 
     if (graphics_) {
       graphics_->finishedClustering(root_cluster_);
@@ -2211,42 +2214,57 @@ void HierRTLMP::breakLargeFlatCluster(Cluster* parent)
   breakLargeFlatCluster(cluster_part_1);
 }
 
-// Break mixed leaves into standard-cell and hard-macro clusters.
-// Merge macros based on connection signature and footprint.
-// Based on types of designs, we support two types of breaking up:
-// Suppose current cluster is A.
-//   1) Replace A by A1, A2, A3
-//   2) Type 2:  Create a subtree:
-//      A  ->        A
-//               |   |   |
-//               A1  A2  A3
-void HierRTLMP::breakMixedLeafCluster(Cluster* root_cluster)
+// Traverse the physical hierarchy tree in a DFS manner (post-order)
+void HierRTLMP::fetchMixedLeaves(
+    Cluster* parent,
+    std::vector<std::vector<Cluster*>>& mixed_leaves)
 {
-  if (root_cluster->getChildren().empty() || root_cluster->getNumMacro() == 0) {
+  if (parent->getChildren().empty() || parent->getNumMacro() == 0) {
     return;
   }
 
-  // Traverse the physical hierarchy tree in a DFS manner (post-order)
-  std::vector<Cluster*> mixed_leaves;
-  for (auto& child : root_cluster->getChildren()) {
+  std::vector<Cluster*> sister_mixed_leaves;
+
+  for (auto& child : parent->getChildren()) {
     setInstProperty(child);
     if (child->getNumMacro() > 0) {
       if (child->getChildren().empty()) {
-        mixed_leaves.push_back(child);
+        sister_mixed_leaves.push_back(child);
       } else {
-        breakMixedLeafCluster(child);
+        fetchMixedLeaves(child, mixed_leaves);
       }
     } else {
       child->setClusterType(StdCellCluster);
     }
   }
 
-  for (auto& mixed_leaf : mixed_leaves) {
-    breakMixedLeaf(mixed_leaf);
-  }
+  // We push the leaves after finishing searching the children so
+  // that each vector of clusters represents the children of one
+  // parent.
+  mixed_leaves.push_back(sister_mixed_leaves);
+}
 
-  // Set the inst property back
-  setInstProperty(root_cluster);
+// Break mixed leaves into standard-cell and hard-macro clusters.
+// Merge macros based on connection signature and footprint.
+// Based on types of designs, we support two types of breaking up:
+// Suppose current cluster is A.
+//   1) Replace A by A1, A2, A3
+//   2) Type 2:  Create a subtree:
+//      A  ->        A
+//               |   |   |
+//               A1  A2  A3
+void HierRTLMP::breakMixedLeaves(
+    const std::vector<std::vector<Cluster*>>& mixed_leaves)
+{
+  for (const std::vector<Cluster*>& sister_mixed_leaves : mixed_leaves) {
+    Cluster* parent = sister_mixed_leaves[0]->getParent();
+
+    for (Cluster* mixed_leaf : sister_mixed_leaves) {
+      breakMixedLeaf(mixed_leaf);
+    }
+
+    setInstProperty(parent);
+  }
 }
 
 void HierRTLMP::breakMixedLeaf(Cluster* mixed_leaf)
diff --git a/src/mpl2/src/hier_rtlmp.h b/src/mpl2/src/hier_rtlmp.h
index 5497f463bbb..18cb999d836 100644
--- a/src/mpl2/src/hier_rtlmp.h
+++ b/src/mpl2/src/hier_rtlmp.h
@@ -203,7 +203,11 @@ class HierRTLMP
   void mergeClusters(std::vector<Cluster*>& candidate_clusters);
   void updateSubTree(Cluster* parent);
   void breakLargeFlatCluster(Cluster* parent);
-  void breakMixedLeafCluster(Cluster* root_cluster);
+
+  void fetchMixedLeaves(Cluster* parent,
+                        std::vector<std::vector<Cluster*>>& mixed_leaves);
+  void breakMixedLeaves(const std::vector<std::vector<Cluster*>>& mixed_leaves);
+
   void breakMixedLeaf(Cluster* mixed_leaf);
   void mapMacroInCluster2HardMacro(Cluster* cluster);
   void createOneClusterForEachMacro(Cluster* parent,