diff --git a/.gitignore b/.gitignore
index 7087f6e030..5f5042e700 100644
--- a/.gitignore
+++ b/.gitignore
@@ -15,12 +15,16 @@ package-lock.json
 !/packages/babel-runtime/core-js/map.js
 /packages/babel-runtime/helpers/*.js
 !/packages/babel-runtime/helpers/toArray.js
+!/packages/babel-runtime/helpers/temporalRef.js
 /packages/babel-runtime/helpers/builtin/*.js
 !/packages/babel-runtime/helpers/builtin/toArray.js
+!/packages/babel-runtime/helpers/builtin/temporalRef.js
 /packages/babel-runtime/helpers/builtin/es6/*.js
 !/packages/babel-runtime/helpers/builtin/es6/toArray.js
+!/packages/babel-runtime/helpers/builtin/es6/temporalRef.js
 /packages/babel-runtime/helpers/es6/*.js
 !/packages/babel-runtime/helpers/es6/toArray.js
+!/packages/babel-runtime/helpers/es6/temporalRef.js
 /packages/babel-register/test/.babel
 /packages/babel-cli/test/tmp
 /packages/babel-node/test/tmp
diff --git a/packages/babel-runtime/helpers/builtin/es6/temporalRef.js b/packages/babel-runtime/helpers/builtin/es6/temporalRef.js
new file mode 100644
index 0000000000..4b0679c64c
--- /dev/null
+++ b/packages/babel-runtime/helpers/builtin/es6/temporalRef.js
@@ -0,0 +1,8 @@
+import undef from "./temporalUndefined";
+export default function _temporalRef(val, name) {
+  if (val === undef) {
+    throw new ReferenceError(name + " is not defined - temporal dead zone");
+  } else {
+    return val;
+  }
+}
\ No newline at end of file
diff --git a/packages/babel-runtime/helpers/builtin/temporalRef.js b/packages/babel-runtime/helpers/builtin/temporalRef.js
new file mode 100644
index 0000000000..20b2652a1f
--- /dev/null
+++ b/packages/babel-runtime/helpers/builtin/temporalRef.js
@@ -0,0 +1,11 @@
+var temporalUndefined = require("./temporalUndefined");
+
+function _temporalRef(val, name) {
+  if (val === temporalUndefined) {
+    throw new ReferenceError(name + " is not defined - temporal dead zone");
+  } else {
+    return val;
+  }
+}
+
+module.exports = _temporalRef;
\ No newline at end of file
diff --git a/packages/babel-runtime/helpers/es6/temporalRef.js b/packages/babel-runtime/helpers/es6/temporalRef.js
new file mode 100644
index 0000000000..4b0679c64c
--- /dev/null
+++ b/packages/babel-runtime/helpers/es6/temporalRef.js
@@ -0,0 +1,8 @@
+import undef from "./temporalUndefined";
+export default function _temporalRef(val, name) {
+  if (val === undef) {
+    throw new ReferenceError(name + " is not defined - temporal dead zone");
+  } else {
+    return val;
+  }
+}
\ No newline at end of file
diff --git a/packages/babel-runtime/helpers/temporalRef.js b/packages/babel-runtime/helpers/temporalRef.js
new file mode 100644
index 0000000000..20b2652a1f
--- /dev/null
+++ b/packages/babel-runtime/helpers/temporalRef.js
@@ -0,0 +1,11 @@
+var temporalUndefined = require("./temporalUndefined");
+
+function _temporalRef(val, name) {
+  if (val === temporalUndefined) {
+    throw new ReferenceError(name + " is not defined - temporal dead zone");
+  } else {
+    return val;
+  }
+}
+
+module.exports = _temporalRef;
\ No newline at end of file