diff --git a/node_16.go b/node_16.go
index 4201599..7c68e0f 100644
--- a/node_16.go
+++ b/node_16.go
@@ -232,7 +232,7 @@ func (n *Node16[T]) LowerBoundIterator() *LowerBoundIterator[T] {
 }
 
 func (n *Node16[T]) incrementLazyRefCount(inc int64) {
-	n.lazyRefCount += inc
+	atomic.AddInt64(&n.lazyRefCount, inc)
 }
 
 func (n *Node16[T]) processRefCount() {
@@ -248,7 +248,7 @@ func (n *Node16[T]) processRefCount() {
 			child.incrementLazyRefCount(n.lazyRefCount)
 		}
 	}
-	n.lazyRefCount = 0
+	atomic.StoreInt64(&n.lazyRefCount, 0)
 }
 
 func (n *Node16[T]) getRefCount() int64 {
diff --git a/node_256.go b/node_256.go
index 08401be..6f14b9b 100644
--- a/node_256.go
+++ b/node_256.go
@@ -229,7 +229,7 @@ func (n *Node256[T]) LowerBoundIterator() *LowerBoundIterator[T] {
 }
 
 func (n *Node256[T]) incrementLazyRefCount(inc int64) {
-	n.lazyRefCount += inc
+	atomic.AddInt64(&n.lazyRefCount, inc)
 }
 
 func (n *Node256[T]) processRefCount() {
@@ -245,7 +245,7 @@ func (n *Node256[T]) processRefCount() {
 			child.incrementLazyRefCount(n.lazyRefCount)
 		}
 	}
-	n.lazyRefCount = 0
+	atomic.StoreInt64(&n.lazyRefCount, 0)
 }
 
 func (n *Node256[T]) getRefCount() int64 {
diff --git a/node_4.go b/node_4.go
index a916c6f..6aa380f 100644
--- a/node_4.go
+++ b/node_4.go
@@ -232,7 +232,7 @@ func (n *Node4[T]) LowerBoundIterator() *LowerBoundIterator[T] {
 }
 
 func (n *Node4[T]) incrementLazyRefCount(inc int64) {
-	n.lazyRefCount += inc
+	atomic.AddInt64(&n.lazyRefCount, inc)
 }
 
 func (n *Node4[T]) processRefCount() {
@@ -248,7 +248,7 @@ func (n *Node4[T]) processRefCount() {
 			child.incrementLazyRefCount(n.lazyRefCount)
 		}
 	}
-	n.lazyRefCount = 0
+	atomic.StoreInt64(&n.lazyRefCount, 0)
 }
 
 func (n *Node4[T]) getRefCount() int64 {
diff --git a/node_48.go b/node_48.go
index 7daeaba..17745f9 100644
--- a/node_48.go
+++ b/node_48.go
@@ -237,7 +237,7 @@ func (n *Node48[T]) LowerBoundIterator() *LowerBoundIterator[T] {
 }
 
 func (n *Node48[T]) incrementLazyRefCount(inc int64) {
-	n.lazyRefCount += inc
+	atomic.AddInt64(&n.lazyRefCount, inc)
 }
 
 func (n *Node48[T]) processRefCount() {
@@ -253,7 +253,7 @@ func (n *Node48[T]) processRefCount() {
 			child.incrementLazyRefCount(n.lazyRefCount)
 		}
 	}
-	n.lazyRefCount = 0
+	atomic.StoreInt64(&n.lazyRefCount, 0)
 }
 
 func (n *Node48[T]) getRefCount() int64 {
diff --git a/node_leaf.go b/node_leaf.go
index fb2a9a7..7f37dfa 100644
--- a/node_leaf.go
+++ b/node_leaf.go
@@ -206,12 +206,12 @@ func (n *NodeLeaf[T]) LowerBoundIterator() *LowerBoundIterator[T] {
 }
 
 func (n *NodeLeaf[T]) incrementLazyRefCount(inc int64) {
-	n.lazyRefCount += inc
+	atomic.AddInt64(&n.lazyRefCount, inc)
 }
 
 func (n *NodeLeaf[T]) processRefCount() {
 	n.refCount += n.lazyRefCount
-	n.lazyRefCount = 0
+	atomic.StoreInt64(&n.lazyRefCount, 0)
 }
 
 func (n *NodeLeaf[T]) getRefCount() int64 {