Try peerDepedencies

Author: schmidt-sebastian

packages/firestore/package.json

@@ -75,11 +75,11 @@
   },
   "peerDependencies": {
     "@firebase/app": "0.x",
+    "@firebase/app-compat": "0.x",
     "@firebase/app-types": "0.x"
   },
   "devDependencies": {
     "@firebase/app": "0.6.12",
-    "@firebase/app-compat": "0.x",
     "@rollup/plugin-alias": "3.1.1",
     "@types/json-stable-stringify": "1.0.32",
     "json-stable-stringify": "1.0.1",