diff --git a/Project.toml b/Project.toml
index 693656a..9f104bc 100644
--- a/Project.toml
+++ b/Project.toml
@@ -12,6 +12,7 @@ ImageMagick = "6218d12a-5da1-5696-b52f-db25d2ecc6d1"
 Images = "916415d5-f1e6-5110-898d-aaa5f9f070e0"
 Interact = "c601a237-2ae4-5e1e-952c-7a85b0c7eef1"
 JSExpr = "97c1335a-c9c5-57fe-bc5d-ec35cebe8660"
+Observables = "510215fc-4207-5dde-b226-833fc4488ee2"
 WebIO = "0f1e0344-ec1d-5b48-a673-e5cf874b6c29"
 Widgets = "cc8bc4a8-27d6-5769-a93b-9d913e69aa62"
 
@@ -23,6 +24,7 @@ ImageMagick = "0.7.5"
 Images = "0.18.0"
 Interact = "0.10.2"
 JSExpr = "0.5.0"
+Observables = "0.2.3"
 WebIO = "0.8.11"
 Widgets = "0.6.2"
 julia = "1.0"