diff --git a/packages/core/package.json b/packages/core/package.json
index df69a9353b..eaf25e07fd 100644
--- a/packages/core/package.json
+++ b/packages/core/package.json
@@ -41,7 +41,8 @@
     "react-router": "^5.2.0",
     "react-router-dom": "^5.2.0",
     "react-sparklines": "^1.7.0",
-    "react-syntax-highlighter": "^12.2.1"
+    "react-syntax-highlighter": "^12.2.1",
+    "zen-observable": "^0.8.15"
   },
   "devDependencies": {
     "@backstage/cli": "^0.1.1-alpha.5",
@@ -55,7 +56,8 @@
     "@types/jest": "^25.2.1",
     "@types/node": "^12.0.0",
     "@types/react-helmet": "^5.0.15",
-    "@types/react-sparklines": "^1.7.0"
+    "@types/react-sparklines": "^1.7.0",
+    "@types/zen-observable": "^0.8.0"
   },
   "files": [
     "dist"