diff --git a/priority_queue/vbt.go b/priority_queue/vbt.go
index 9f7c61b..393f90b 100644
--- a/priority_queue/vbt.go
+++ b/priority_queue/vbt.go
@@ -440,7 +440,7 @@ func (tree *vbTree) Put(key interface{}) *tNode {
 			ls, rs := cur.children[0].size, cur.children[1].size
 			factor := cur.size / 10 // or factor = 1
 			if rs >= ls*2+factor || ls >= rs*2+factor {
-				tree.fixSize(cur, ls, rs)
+				cur = tree.fixSize(cur, ls, rs)
 			}
 		}
 
@@ -640,13 +640,16 @@ func (tree *vbTree) lrrotate(cur *tNode) *tNode {
 		} else {
 			cur.parent.children[r] = lrn
 		}
+	} else {
+		tree.root = lrn
 	}
+	lrn.parent = cur.parent
 
 	lrn.children[l] = cur.children[l]
 	lrn.children[l].parent = lrn
 
-	lrn.children[l] = cur
-	lrn.children[l].parent = lrn
+	lrn.children[r] = cur
+	lrn.children[r].parent = lrn
 
 	cur.children[l] = lrrn
 	cur.children[l].parent = cur
@@ -701,13 +704,16 @@ func (tree *vbTree) rlrotate(cur *tNode) *tNode {
 		} else {
 			cur.parent.children[r] = lrn
 		}
+	} else {
+		tree.root = lrn
 	}
+	lrn.parent = cur.parent
 
 	lrn.children[l] = cur.children[l]
 	lrn.children[l].parent = lrn
 
-	lrn.children[l] = cur
-	lrn.children[l].parent = lrn
+	lrn.children[r] = cur
+	lrn.children[r].parent = lrn
 
 	cur.children[l] = lrrn
 	cur.children[l].parent = cur
@@ -752,6 +758,8 @@ func (tree *vbTree) rrotate(cur *tNode) *tNode {
 		} else {
 			cur.parent.children[r] = ln
 		}
+	} else {
+		tree.root = ln
 	}
 	ln.parent = cur.parent
 
@@ -802,6 +810,8 @@ func (tree *vbTree) lrotate(cur *tNode) *tNode {
 		} else {
 			cur.parent.children[r] = ln
 		}
+	} else {
+		tree.root = ln
 	}
 	ln.parent = cur.parent