diff --git a/ui/filetreeview.go b/ui/filetreeview.go
index 38f8701..1a1bdc2 100644
--- a/ui/filetreeview.go
+++ b/ui/filetreeview.go
@@ -116,6 +116,8 @@ func (view *FileTreeView) setLayer(layerIndex int) error {
 }
 
 func (view *FileTreeView) CursorDown() error {
+	// cannot easily (quickly) check the model length, allow the view
+	// to let us know what is a valid bounds (i.e. when it hits an empty line)
 	err := CursorDown(view.gui, view.view)
 	if err == nil {
 		view.TreeIndex++
@@ -124,9 +126,11 @@ func (view *FileTreeView) CursorDown() error {
 }
 
 func (view *FileTreeView) CursorUp() error {
-	err := CursorUp(view.gui, view.view)
-	if err == nil {
-		view.TreeIndex--
+	if view.TreeIndex > 0 {
+		err := CursorUp(view.gui, view.view)
+		if err == nil {
+			view.TreeIndex--
+		}
 	}
 	return view.Render()
 }
diff --git a/ui/layerview.go b/ui/layerview.go
index 77c3e6f..d100194 100644
--- a/ui/layerview.go
+++ b/ui/layerview.go
@@ -79,7 +79,7 @@ func (view *LayerView) Render() error {
 }
 
 func (view *LayerView) CursorDown() error {
-	if int(view.LayerIndex) < len(view.Layers) {
+	if view.LayerIndex < len(view.Layers) {
 		err := CursorDown(view.gui, view.view)
 		if err == nil {
 			view.LayerIndex++
@@ -91,7 +91,7 @@ func (view *LayerView) CursorDown() error {
 }
 
 func (view *LayerView) CursorUp() error {
-	if int(view.LayerIndex) > 0 {
+	if view.LayerIndex > 0 {
 		err := CursorUp(view.gui, view.view)
 		if err == nil {
 			view.LayerIndex--
diff --git a/ui/ui.go b/ui/ui.go
index 0ac6759..434adfd 100644
--- a/ui/ui.go
+++ b/ui/ui.go
@@ -7,6 +7,7 @@ import (
 	"github.com/wagoodman/docker-image-explorer/filetree"
 	"github.com/wagoodman/docker-image-explorer/image"
 	"github.com/fatih/color"
+	"github.com/wagoodman/docker-image-explorer/_vendor-20180604210951/github.com/pkg/errors"
 )
 
 const debug = false
@@ -51,7 +52,7 @@ func CursorDown(g *gocui.Gui, v *gocui.View) error {
 		// todo: handle error
 	}
 	if len(line) == 0 {
-		return nil
+		return errors.New("unable to move cursor down, empty line")
 	}
 	if err := v.SetCursor(cx, cy+1); err != nil {
 		ox, oy := v.Origin()