diff --git a/package.json b/package.json
index 6deac7c..49315be 100644
--- a/package.json
+++ b/package.json
@@ -46,6 +46,14 @@
 		"xo": "^0.24.0",
 		"zen-observable": "^0.8.8"
 	},
+	"peerDependenciesMeta": {
+		"rxjs": {
+			"optional": true
+		},
+		"zen-observable": {
+			"optional": true
+		}
+	},
 	"browser": {
 		"./register.js": "./register-shim.js"
 	},