diff --git a/package.json b/package.json
index 7b25e1da310..c7580abce8a 100644
--- a/package.json
+++ b/package.json
@@ -17,8 +17,11 @@
   "module": "./dist/index.js",
   "types": "./dist/index.d.ts",
   "sideEffects": [
-    "./dist/cache/inmemory/fixPolyfills.js"
+    "./dist/cache/inmemory/fixPolyfills.native.js"
   ],
+  "react-native": {
+    "./dist/cache/inmemory/fixPolyfills.js": "./dist/cache/inmemory/fixPolyfills.native.js"
+  },
   "repository": {
     "type": "git",
     "url": "git+https://github.com/apollographql/apollo-client.git"
@@ -48,7 +51,7 @@
     {
       "name": "apollo-client",
       "path": "./dist/apollo-client.cjs.min.js",
-      "maxSize": "24.2 kB"
+      "maxSize": "24 kB"
     }
   ],
   "peerDependencies": {
diff --git a/src/cache/inmemory/fixPolyfills.native.ts b/src/cache/inmemory/fixPolyfills.native.ts
new file mode 100644
index 00000000000..98b55ae5419
--- /dev/null
+++ b/src/cache/inmemory/fixPolyfills.native.ts
@@ -0,0 +1,53 @@
+// Make sure Map.prototype.set returns the Map instance, per spec.
+// https://github.com/apollographql/apollo-client/issues/4024
+const testMap = new Map();
+if (testMap.set(1, 2) !== testMap) {
+  const { set } = testMap;
+  Map.prototype.set = function (...args) {
+    set.apply(this, args);
+    return this;
+  };
+}
+
+// Make sure Set.prototype.add returns the Set instance, per spec.
+const testSet = new Set();
+if (testSet.add(3) !== testSet) {
+  const { add } = testSet;
+  Set.prototype.add = function (...args) {
+    add.apply(this, args);
+    return this;
+  };
+}
+
+const frozen = {};
+if (typeof Object.freeze === 'function') {
+  Object.freeze(frozen);
+}
+
+try {
+  // If non-extensible objects can't be stored as keys in a Map, make sure we
+  // do not freeze/seal/etc. an object without first attempting to put it in a
+  // Map. For example, this gives the React Native Map polyfill a chance to tag
+  // objects before they become non-extensible:
+  // https://github.com/facebook/react-native/blob/98a6f19d7c/Libraries/vendor/core/Map.js#L44-L50
+  // https://github.com/apollographql/react-apollo/issues/2442#issuecomment-426489517
+  testMap.set(frozen, frozen).delete(frozen);
+} catch {
+  const wrap = (method: <T>(obj: T) => T): typeof method => {
+    return method && (obj => {
+      try {
+        // If .set succeeds, also call .delete to avoid leaking memory.
+        testMap.set(obj, obj).delete(obj);
+      } finally {
+        // If .set or .delete fails, the exception will be silently swallowed
+        // by this return-from-finally statement:
+        return method.call(Object, obj);
+      }
+    });
+  };
+  Object.freeze = wrap(Object.freeze);
+  Object.seal = wrap(Object.seal);
+  Object.preventExtensions = wrap(Object.preventExtensions);
+}
+
+export {}
diff --git a/src/cache/inmemory/fixPolyfills.ts b/src/cache/inmemory/fixPolyfills.ts
index 98b55ae5419..4fbe4fd9965 100644
--- a/src/cache/inmemory/fixPolyfills.ts
+++ b/src/cache/inmemory/fixPolyfills.ts
@@ -1,53 +1,7 @@
-// Make sure Map.prototype.set returns the Map instance, per spec.
-// https://github.com/apollographql/apollo-client/issues/4024
-const testMap = new Map();
-if (testMap.set(1, 2) !== testMap) {
-  const { set } = testMap;
-  Map.prototype.set = function (...args) {
-    set.apply(this, args);
-    return this;
-  };
-}
-
-// Make sure Set.prototype.add returns the Set instance, per spec.
-const testSet = new Set();
-if (testSet.add(3) !== testSet) {
-  const { add } = testSet;
-  Set.prototype.add = function (...args) {
-    add.apply(this, args);
-    return this;
-  };
-}
-
-const frozen = {};
-if (typeof Object.freeze === 'function') {
-  Object.freeze(frozen);
-}
-
-try {
-  // If non-extensible objects can't be stored as keys in a Map, make sure we
-  // do not freeze/seal/etc. an object without first attempting to put it in a
-  // Map. For example, this gives the React Native Map polyfill a chance to tag
-  // objects before they become non-extensible:
-  // https://github.com/facebook/react-native/blob/98a6f19d7c/Libraries/vendor/core/Map.js#L44-L50
-  // https://github.com/apollographql/react-apollo/issues/2442#issuecomment-426489517
-  testMap.set(frozen, frozen).delete(frozen);
-} catch {
-  const wrap = (method: <T>(obj: T) => T): typeof method => {
-    return method && (obj => {
-      try {
-        // If .set succeeds, also call .delete to avoid leaking memory.
-        testMap.set(obj, obj).delete(obj);
-      } finally {
-        // If .set or .delete fails, the exception will be silently swallowed
-        // by this return-from-finally statement:
-        return method.call(Object, obj);
-      }
-    });
-  };
-  Object.freeze = wrap(Object.freeze);
-  Object.seal = wrap(Object.seal);
-  Object.preventExtensions = wrap(Object.preventExtensions);
-}
-
-export {}
+// Most JavaScript environments do not need the workarounds implemented in
+// fixPolyfills.native.ts, so importing fixPolyfills.ts merely imports
+// this empty module, adding nothing to bundle sizes or execution times.
+// When bundling for React Native, we substitute fixPolyfills.native.js
+// for fixPolyfills.js (see the "react-native" section of package.json),
+// to work around problems with Map and Set polyfills in older versions of
+// React Native (which should have been fixed in react-native@0.59.0).