diff --git a/packages/apollo-boost/package.json b/packages/apollo-boost/package.json
index 81e7c7db06e..1869388a0a9 100644
--- a/packages/apollo-boost/package.json
+++ b/packages/apollo-boost/package.json
@@ -11,6 +11,7 @@
   "license": "MIT",
   "main": "./lib/index.js",
   "typings": "./lib/index.d.ts",
+  "sideEffects": false,
   "repository": {
     "type": "git",
     "url": "git+https://github.com/apollographql/apollo-client.git"
diff --git a/packages/apollo-cache-inmemory/package.json b/packages/apollo-cache-inmemory/package.json
index 42c24893e8c..25c9de56a96 100644
--- a/packages/apollo-cache-inmemory/package.json
+++ b/packages/apollo-cache-inmemory/package.json
@@ -15,6 +15,7 @@
   "module": "./lib/index.js",
   "jsnext:main": "./lib/index.js",
   "typings": "./lib/index.d.ts",
+  "sideEffects": false,
   "repository": {
     "type": "git",
     "url": "git+https://github.com/apollographql/apollo-client.git"
diff --git a/packages/apollo-cache/package.json b/packages/apollo-cache/package.json
index 80793811bf8..ce351a9966f 100644
--- a/packages/apollo-cache/package.json
+++ b/packages/apollo-cache/package.json
@@ -14,6 +14,7 @@
   "module": "./lib/index.js",
   "jsnext:main": "./lib/index.js",
   "typings": "./lib/index.d.ts",
+  "sideEffects": false,
   "repository": {
     "type": "git",
     "url": "git+https://github.com/apollographql/apollo-client.git"
diff --git a/packages/apollo-client/package.json b/packages/apollo-client/package.json
index 786c3630fbd..5863931e854 100644
--- a/packages/apollo-client/package.json
+++ b/packages/apollo-client/package.json
@@ -7,6 +7,7 @@
   "module": "./lib/index.js",
   "jsnext:main": "./lib/index.js",
   "typings": "./lib/index.d.ts",
+  "sideEffects": false,
   "scripts": {
     "coverage": "jest --coverage",
     "dev": "./scripts/dev.sh",
diff --git a/packages/apollo-utilities/package.json b/packages/apollo-utilities/package.json
index e71fb97cafa..a26cc0ab586 100644
--- a/packages/apollo-utilities/package.json
+++ b/packages/apollo-utilities/package.json
@@ -14,6 +14,7 @@
   "module": "./lib/index.js",
   "jsnext:main": "./lib/index.js",
   "typings": "./lib/index.d.ts",
+  "sideEffects": false,
   "repository": {
     "type": "git",
     "url": "git+https://github.com/apollographql/apollo-client.git"
diff --git a/packages/graphql-anywhere/package.json b/packages/graphql-anywhere/package.json
index 9ea158d813d..68fd8517929 100644
--- a/packages/graphql-anywhere/package.json
+++ b/packages/graphql-anywhere/package.json
@@ -6,6 +6,7 @@
   "module": "./lib/index.js",
   "jsnext:main": "./lib/index.js",
   "typings": "./lib/index.d.ts",
+  "sideEffects": false,
   "scripts": {
     "coverage": "jest --coverage",
     "test": "jest",