diff --git a/docker/models.go b/docker/models.go
index 04e6e7a..ea04782 100644
--- a/docker/models.go
+++ b/docker/models.go
@@ -188,6 +188,11 @@ func (s *Service) UnmarshalJSON(data []byte) error {
 		imageName = imageNameParts[0]
 	}
 
+	tag := "?"
+	if len(imageNameParts) > 1 {
+		tag = imageNameParts[1]
+	}
+
 	appName := ci.Details[0].Spec.Labels.Namespace
 
 	*s = Service{
@@ -199,7 +204,7 @@ func (s *Service) UnmarshalJSON(data []byte) error {
 			Tag  string
 		}{
 			Name: imageName,
-			Tag:  imageNameParts[1],
+			Tag:  tag,
 		},
 		Networks: networks,
 		Ports:    ci.Details[0].Endpoint.Ports,