diff --git a/src/libslic3r/BranchingTree/BranchingTree.cpp b/src/libslic3r/BranchingTree/BranchingTree.cpp
index a7d9a1b4d..3102f213f 100644
--- a/src/libslic3r/BranchingTree/BranchingTree.cpp
+++ b/src/libslic3r/BranchingTree/BranchingTree.cpp
@@ -106,7 +106,11 @@ bool build_tree(PointCloud &nodes, Builder &builder)
                             mergenode.right = closest_node_id;
                             size_t new_idx = nodes.insert_junction(mergenode);
                             ptsqueue.push(new_idx);
-                            ptsqueue.remove(nodes.get_queue_idx(closest_node_id));
+                            size_t qid = nodes.get_queue_idx(closest_node_id);
+
+                            if (qid != PointCloud::Unqueued)
+                                ptsqueue.remove(nodes.get_queue_idx(closest_node_id));
+
                             nodes.mark_unreachable(closest_node_id);
                         }
                     } else if (closest_node.pos.z() < node.pos.z() &&
diff --git a/src/libslic3r/BranchingTree/PointCloud.cpp b/src/libslic3r/BranchingTree/PointCloud.cpp
index 35498f4c1..11b500843 100644
--- a/src/libslic3r/BranchingTree/PointCloud.cpp
+++ b/src/libslic3r/BranchingTree/PointCloud.cpp
@@ -140,7 +140,7 @@ PointCloud::PointCloud(std::vector<Node> meshpts,
     , LEAFS_BEGIN{MESHPTS_BEGIN + m_meshpoints.size()}
     , JUNCTIONS_BEGIN{LEAFS_BEGIN + m_leafs.size()}
     , m_searchable_indices(JUNCTIONS_BEGIN + m_junctions.size(), true)
-    , m_queue_indices(JUNCTIONS_BEGIN + m_junctions.size(), UNQUEUED)
+    , m_queue_indices(JUNCTIONS_BEGIN + m_junctions.size(), Unqueued)
     , m_reachable_cnt{JUNCTIONS_BEGIN + m_junctions.size()}
     , m_ktree{CoordFn{this}, LEAFS_BEGIN} // Only for bed and mesh points
 {
diff --git a/src/libslic3r/BranchingTree/PointCloud.hpp b/src/libslic3r/BranchingTree/PointCloud.hpp
index d2072bee9..3c5e8a9a2 100644
--- a/src/libslic3r/BranchingTree/PointCloud.hpp
+++ b/src/libslic3r/BranchingTree/PointCloud.hpp
@@ -67,8 +67,6 @@ private:
         return dot_sq < D.squaredNorm() * cos2bridge_slope;
     }
 
-    static constexpr auto UNQUEUED = size_t(-1);
-
     template<class PC>
     static auto *get_node(PC &&pc, size_t id)
     {
@@ -87,6 +85,8 @@ private:
 
 public:
 
+    static constexpr auto Unqueued = size_t(-1);
+
     struct ZCompareFn
     {
         const PointCloud *self;
@@ -155,7 +155,7 @@ public:
         m_junctions.emplace_back(p);
         m_junctions.back().id = int(new_id);
         m_searchable_indices.emplace_back(true);
-        m_queue_indices.emplace_back(UNQUEUED);
+        m_queue_indices.emplace_back(Unqueued);
         ++m_reachable_cnt;
 
         return new_id;
@@ -172,7 +172,7 @@ public:
         assert(node_id < m_searchable_indices.size());
 
         m_searchable_indices[node_id] = false;
-        m_queue_indices[node_id] = UNQUEUED;
+        m_queue_indices[node_id] = Unqueued;
         --m_reachable_cnt;
     }