diff --git a/pubspec.yaml b/pubspec.yaml
index 11e0382c38..f7a02830ad 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -2,7 +2,7 @@ name: angular
 environment:
   sdk: '>=1.12.0-dev.5.10 <2.0.0'
 dependencies:
-  observe: '0.13.1'
+  observe: '^0.13.1'
 dev_dependencies:
   guinness: '^0.1.17'
   intl: '^0.12.4'