diff --git a/packages/signature-v4-crt/package.json b/packages/signature-v4-crt/package.json
index 11393a968332..d790a4f38bb6 100644
--- a/packages/signature-v4-crt/package.json
+++ b/packages/signature-v4-crt/package.json
@@ -21,6 +21,7 @@
     "url": "https://aws.amazon.com/javascript/"
   },
   "license": "Apache-2.0",
+  "sideEffects": true,
   "dependencies": {
     "@aws-sdk/crt-loader": "*",
     "@aws-sdk/signature-v4-multi-region": "*",
diff --git a/packages/util-endpoints/package.json b/packages/util-endpoints/package.json
index bb78d5d2f374..9ef045dd790a 100644
--- a/packages/util-endpoints/package.json
+++ b/packages/util-endpoints/package.json
@@ -23,6 +23,7 @@
     "url": "https://aws.amazon.com/javascript/"
   },
   "license": "Apache-2.0",
+  "sideEffects": true,
   "dependencies": {
     "@aws-sdk/types": "*",
     "@smithy/types": "^4.3.1",