diff --git a/Gopkg.lock b/Gopkg.lock
index 405f1a25..38f92e16 100644
--- a/Gopkg.lock
+++ b/Gopkg.lock
@@ -50,7 +50,7 @@
   branch = "master"
   name = "github.com/hashicorp/go-immutable-radix"
   packages = ["."]
-  revision = "59b67882ec612f43b9d4c4fd97cebd507be4b3ee"
+  revision = "7f3cd4390caab3250a57f30efdb2a65dd7649ecf"
 
 [[projects]]
   branch = "master"
@@ -115,7 +115,7 @@
     "poly1305",
     "salsa20/salsa"
   ]
-  revision = "3d37316aaa6bd9929127ac9a527abf408178ea7b"
+  revision = "1875d0a70c90e57f11972aefd42276df65e895b9"
 
 [[projects]]
   branch = "master"
@@ -139,7 +139,7 @@
     "windows/svc/eventlog",
     "windows/svc/mgr"
   ]
-  revision = "ef802241c90f84d84d644a2d8d0de8ee96038c9c"
+  revision = "3dbebcf8efb6a5011a60c2b4591c1022a759af8a"
 
 [solve-meta]
   analyzer-name = "dep"
diff --git a/vendor/github.com/hashicorp/go-immutable-radix/iradix.go b/vendor/github.com/hashicorp/go-immutable-radix/iradix.go
index c7172c40..e5e6e57f 100644
--- a/vendor/github.com/hashicorp/go-immutable-radix/iradix.go
+++ b/vendor/github.com/hashicorp/go-immutable-radix/iradix.go
@@ -338,6 +338,11 @@ func (t *Txn) delete(parent, n *Node, search []byte) (*Node, *leafNode) {
 		if !n.isLeaf() {
 			return nil, nil
 		}
+		// Copy the pointer in case we are in a transaction that already
+		// modified this node since the node will be reused. Any changes
+		// made to the node will not affect returning the original leaf
+		// value.
+		oldLeaf := n.leaf
 
 		// Remove the leaf node
 		nc := t.writeNode(n, true)
@@ -347,7 +352,7 @@ func (t *Txn) delete(parent, n *Node, search []byte) (*Node, *leafNode) {
 		if n != t.root && len(nc.edges) == 1 {
 			t.mergeChild(nc)
 		}
-		return nc, n.leaf
+		return nc, oldLeaf
 	}
 
 	// Look for an edge
diff --git a/vendor/github.com/hashicorp/go-immutable-radix/iradix_test.go b/vendor/github.com/hashicorp/go-immutable-radix/iradix_test.go
index bc9c77c2..326299de 100644
--- a/vendor/github.com/hashicorp/go-immutable-radix/iradix_test.go
+++ b/vendor/github.com/hashicorp/go-immutable-radix/iradix_test.go
@@ -173,7 +173,7 @@ func TestRoot(t *testing.T) {
 	}
 	val, ok := r.Get(nil)
 	if !ok || val != true {
-		t.Fatalf("bad: %v %#v", val)
+		t.Fatalf("bad: %#v", val)
 	}
 	r, val, ok = r.Delete(nil)
 	if !ok || val != true {
@@ -1494,3 +1494,38 @@ func TestTrackMutate_cachedNodeChange(t *testing.T) {
 		}
 	}
 }
+
+func TestLenTxn(t *testing.T) {
+	r := New()
+
+	if r.Len() != 0 {
+		t.Fatalf("not starting with empty tree")
+	}
+
+	txn := r.Txn()
+	keys := []string{
+		"foo/bar/baz",
+		"foo/baz/bar",
+		"foo/zip/zap",
+		"foobar",
+		"nochange",
+	}
+	for _, k := range keys {
+		txn.Insert([]byte(k), nil)
+	}
+	r = txn.Commit()
+
+	if r.Len() != len(keys) {
+		t.Fatalf("bad: expected %d, got %d", len(keys), r.Len())
+	}
+
+	txn = r.Txn()
+	for _, k := range keys {
+		txn.Delete([]byte(k))
+	}
+	r = txn.Commit()
+
+	if r.Len() != 0 {
+		t.Fatalf("tree len should be zero, got %d", r.Len())
+	}
+}