diff --git a/packages/babel-plugin-transform-optional-chaining/src/index.js b/packages/babel-plugin-transform-optional-chaining/src/index.js
index c2ddf4965b..75fff8aabc 100644
--- a/packages/babel-plugin-transform-optional-chaining/src/index.js
+++ b/packages/babel-plugin-transform-optional-chaining/src/index.js
@@ -1,5 +1,5 @@
 export default function ({ types: t }) {
-  const nilIdentifier = t.identifier("undefined");
+  const nilIdentifier = t.unaryExpression("void", t.numericLiteral(0));
 
   function setOptionalTransformed(node) {
     t.assertMemberExpression(node); // Dev
diff --git a/packages/babel-plugin-transform-optional-chaining/test/fixtures/general/assignement/expected.js b/packages/babel-plugin-transform-optional-chaining/test/fixtures/general/assignement/expected.js
index a4c87fdf0c..28f9f5b1e2 100644
--- a/packages/babel-plugin-transform-optional-chaining/test/fixtures/general/assignement/expected.js
+++ b/packages/babel-plugin-transform-optional-chaining/test/fixtures/general/assignement/expected.js
@@ -1,9 +1,9 @@
 var _temp;
 
-if (((_temp = a) != null ? _temp.b : undefined) != undefined) {
+if (((_temp = a) != null ? _temp.b : void 0) != void 0) {
   a.b = 42;
 }
 
-if (((_temp = a.b.c) != null ? _temp.d : undefined) != undefined) {
+if (((_temp = a.b.c) != null ? _temp.d : void 0) != void 0) {
   a.b.c.d = 42;
-}
\ No newline at end of file
+}
diff --git a/packages/babel-plugin-transform-optional-chaining/test/fixtures/general/delete/expected.js b/packages/babel-plugin-transform-optional-chaining/test/fixtures/general/delete/expected.js
index ec0bfb91c3..a2fd158a7c 100644
--- a/packages/babel-plugin-transform-optional-chaining/test/fixtures/general/delete/expected.js
+++ b/packages/babel-plugin-transform-optional-chaining/test/fixtures/general/delete/expected.js
@@ -1,9 +1,9 @@
 var _temp;
 
-if (((_temp = a) != null ? _temp.b : undefined) != undefined) {
+if (((_temp = a) != null ? _temp.b : void 0) != void 0) {
   delete a.b;
 }
 
-if (((_temp = ((_temp = a) != null ? _temp.b : undefined).c) != null ? _temp.d : undefined) != undefined) {
-  delete ((_temp = a.b) != null ? _temp.c : undefined).d;
-}
\ No newline at end of file
+if (((_temp = ((_temp = a) != null ? _temp.b : void 0).c) != null ? _temp.d : void 0) != void 0) {
+  delete ((_temp = a.b) != null ? _temp.c : void 0).d;
+}
diff --git a/packages/babel-plugin-transform-optional-chaining/test/fixtures/general/function-call/expected.js b/packages/babel-plugin-transform-optional-chaining/test/fixtures/general/function-call/expected.js
index b20ea71dac..141f7dd896 100644
--- a/packages/babel-plugin-transform-optional-chaining/test/fixtures/general/function-call/expected.js
+++ b/packages/babel-plugin-transform-optional-chaining/test/fixtures/general/function-call/expected.js
@@ -1,3 +1,3 @@
 var _temp;
 
-((_temp = foo) != null ? _temp.bar : Function())();
\ No newline at end of file
+((_temp = foo) != null ? _temp.bar : Function())();
diff --git a/packages/babel-plugin-transform-optional-chaining/test/fixtures/general/member-access/expected.js b/packages/babel-plugin-transform-optional-chaining/test/fixtures/general/member-access/expected.js
index 013c8d6f86..fe9a91bd04 100644
--- a/packages/babel-plugin-transform-optional-chaining/test/fixtures/general/member-access/expected.js
+++ b/packages/babel-plugin-transform-optional-chaining/test/fixtures/general/member-access/expected.js
@@ -1,5 +1,5 @@
 var _temp;
 
-(_temp = foo) != null ? _temp.bar : undefined;
+(_temp = foo) != null ? _temp.bar : void 0;
 
-((_temp = ((_temp = a) != null ? _temp.b : undefined).c) != null ? _temp.d : undefined).e;
\ No newline at end of file
+((_temp = ((_temp = a) != null ? _temp.b : void 0).c) != null ? _temp.d : void 0).e;