diff --git a/packages/babel-helpers/scripts/generate-helpers.js b/packages/babel-helpers/scripts/generate-helpers.js
index e0b37019320f..2bf301f4a773 100644
--- a/packages/babel-helpers/scripts/generate-helpers.js
+++ b/packages/babel-helpers/scripts/generate-helpers.js
@@ -47,8 +47,12 @@ export default Object.freeze({
 
     const source = await minify(fileContents, {
       mangle: false,
-      // The _typeof helper has a custom directive that we must keep
-      compress: { directives: false },
+      compress: {
+        // The _typeof helper has a custom directive that we must keep
+        directives: false,
+        // The _checkInRHS helper has `0 in value` which does have side effects
+        side_effects: false,
+      },
     });
 
     output += `\
diff --git a/packages/babel-helpers/src/helpers-generated.ts b/packages/babel-helpers/src/helpers-generated.ts
index e7eabc002073..c9ca232fbde2 100644
--- a/packages/babel-helpers/src/helpers-generated.ts
+++ b/packages/babel-helpers/src/helpers-generated.ts
@@ -43,7 +43,7 @@ export default Object.freeze({
   ),
   checkInRHS: helper(
     "7.20.1",
-    "export default function _checkInRHS(value){return value}",
+    "export default function _checkInRHS(value){return 0 in value,value}",
   ),
   jsx: helper(
     "7.0.0-beta.0",