diff --git a/vendor/github.com/hashicorp/go-immutable-radix/iter.go b/vendor/github.com/hashicorp/go-immutable-radix/iter.go
index 9815e02..1ecaf83 100644
--- a/vendor/github.com/hashicorp/go-immutable-radix/iter.go
+++ b/vendor/github.com/hashicorp/go-immutable-radix/iter.go
@@ -1,6 +1,8 @@
 package iradix
 
-import "bytes"
+import (
+	"bytes"
+)
 
 // Iterator is used to iterate over a set of nodes
 // in pre-order
@@ -53,6 +55,101 @@
 	i.SeekPrefixWatch(prefix)
 }
 
+func (i *Iterator) recurseMin(n *Node) *Node {
+	// Traverse to the minimum child
+	if n.leaf != nil {
+		return n
+	}
+	if len(n.edges) > 0 {
+		// Add all the other edges to the stack (the min node will be added as
+		// we recurse)
+		i.stack = append(i.stack, n.edges[1:])
+		return i.recurseMin(n.edges[0].node)
+	}
+	// Shouldn't be possible
+	return nil
+}
+
+// SeekLowerBound is used to seek the iterator to the smallest key that is
+// greater or equal to the given key. There is no watch variant as it's hard to
+// predict based on the radix structure which node(s) changes might affect the
+// result.
+func (i *Iterator) SeekLowerBound(key []byte) {
+	// Wipe the stack. Unlike Prefix iteration, we need to build the stack as we
+	// go because we need only a subset of edges of many nodes in the path to the
+	// leaf with the lower bound.
+	i.stack = []edges{}
+	n := i.node
+	search := key
+
+	found := func(n *Node) {
+		i.node = n
+		i.stack = append(i.stack, edges{edge{node: n}})
+	}
+
+	for {
+		// Compare current prefix with the search key's same-length prefix.
+		var prefixCmp int
+		if len(n.prefix) < len(search) {
+			prefixCmp = bytes.Compare(n.prefix, search[0:len(n.prefix)])
+		} else {
+			prefixCmp = bytes.Compare(n.prefix, search)
+		}
+
+		if prefixCmp > 0 {
+			// Prefix is larger, that means the lower bound is greater than the search
+			// and from now on we need to follow the minimum path to the smallest
+			// leaf under this subtree.
+			n = i.recurseMin(n)
+			if n != nil {
+				found(n)
+			}
+			return
+		}
+
+		if prefixCmp < 0 {
+			// Prefix is smaller than search prefix, that means there is no lower
+			// bound
+			i.node = nil
+			return
+		}
+
+		// Prefix is equal, we are still heading for an exact match. If this is a
+		// leaf we're done.
+		if n.leaf != nil {
+			if bytes.Compare(n.leaf.key, key) < 0 {
+				i.node = nil
+				return
+			}
+			found(n)
+			return
+		}
+
+		// Consume the search prefix
+		if len(n.prefix) > len(search) {
+			search = []byte{}
+		} else {
+			search = search[len(n.prefix):]
+		}
+
+		// Otherwise, take the lower bound next edge.
+		idx, lbNode := n.getLowerBoundEdge(search[0])
+		if lbNode == nil {
+			i.node = nil
+			return
+		}
+
+		// Create stack edges for the all strictly higher edges in this node.
+		if idx+1 < len(n.edges) {
+			i.stack = append(i.stack, n.edges[idx+1:])
+		}
+
+		i.node = lbNode
+		// Recurse
+		n = lbNode
+	}
+}
+
 // Next returns the next node in order
 func (i *Iterator) Next() ([]byte, interface{}, bool) {
 	// Initialize our stack if needed