diff --git a/daemon/images/service.go b/daemon/images/service.go
index 70a8bf4455..4af48959bf 100644
--- a/daemon/images/service.go
+++ b/daemon/images/service.go
@@ -77,7 +77,7 @@ type ImageService struct {
 // CountImages returns the number of images stored by ImageService
 // called from info.go
 func (i *ImageService) CountImages() int {
-	return len(i.imageStore.Map())
+	return i.imageStore.Len()
 }
 
 // Children returns the children image.IDs for a parent image.
diff --git a/image/store.go b/image/store.go
index a8f8cee5b2..9fd7d7dcf3 100644
--- a/image/store.go
+++ b/image/store.go
@@ -27,6 +27,7 @@ type Store interface {
 	Children(id ID) []ID
 	Map() map[ID]*Image
 	Heads() map[ID]*Image
+	Len() int
 }
 
 // LayerGetReleaser is a minimal interface for getting and releasing images.
@@ -336,3 +337,9 @@ func (is *store) imagesMap(all bool) map[ID]*Image {
 	}
 	return images
 }
+
+func (is *store) Len() int {
+	is.RLock()
+	defer is.RUnlock()
+	return len(is.images)
+}