diff --git a/packages/flutter_mozilla_components/javascript/container_proxy/package-lock.json b/packages/flutter_mozilla_components/javascript/container_proxy/package-lock.json
index ead627f5..c809c52e 100644
--- a/packages/flutter_mozilla_components/javascript/container_proxy/package-lock.json
+++ b/packages/flutter_mozilla_components/javascript/container_proxy/package-lock.json
@@ -15,6 +15,7 @@
         "addons-linter": "^7.8.0",
         "chai": "^5.1.2",
         "copy-webpack-plugin": "^12.0.2",
+        "esm": "^3.2.25",
         "mocha": "^10.8.2",
         "sinon": "^8.1.1",
         "standardx": "^7.0.0",
@@ -4797,6 +4798,16 @@
       "dev": true,
       "license": "MIT"
     },
+    "node_modules/esm": {
+      "version": "3.2.25",
+      "resolved": "https://registry.npmjs.org/esm/-/esm-3.2.25.tgz",
+      "integrity": "sha512-U1suiZ2oDVWv4zPO56S0NcR5QriEahGtdN2OR6FiOG4WJvcjBVFB0qI4+eKoWFH483PKGuLuu6V8Z4T5g63UVA==",
+      "dev": true,
+      "license": "MIT",
+      "engines": {
+        "node": ">=6"
+      }
+    },
     "node_modules/espree": {
       "version": "10.4.0",
       "resolved": "https://registry.npmjs.org/espree/-/espree-10.4.0.tgz",
diff --git a/packages/flutter_mozilla_components/javascript/container_proxy/package.json b/packages/flutter_mozilla_components/javascript/container_proxy/package.json
index c932c4b2..0e4b2019 100644
--- a/packages/flutter_mozilla_components/javascript/container_proxy/package.json
+++ b/packages/flutter_mozilla_components/javascript/container_proxy/package.json
@@ -37,6 +37,7 @@
     "addons-linter": "^7.8.0",
     "chai": "^5.1.2",
     "copy-webpack-plugin": "^12.0.2",
+    "esm": "^3.2.25",
     "mocha": "^10.8.2",
     "sinon": "^8.1.1",
     "standardx": "^7.0.0",