diff --git a/lib/APIPlugin.js b/lib/APIPlugin.js
index 6cd80646dcd..bc084f011bc 100644
--- a/lib/APIPlugin.js
+++ b/lib/APIPlugin.js
@@ -58,12 +58,12 @@ class APIPlugin {
 											REPLACEMENTS[key]
 									  )
 							);
-						parser.hooks.evaluateTypeof
-							.for(key)
-							.tap(
-								"APIPlugin",
-								ParserHelpers.evaluateToString(REPLACEMENT_TYPES[key])
-							);
+						const type = REPLACEMENT_TYPES[key];
+						if (type) {
+							parser.hooks.evaluateTypeof
+								.for(key)
+								.tap("APIPlugin", ParserHelpers.evaluateToString(type));
+						}
 					});
 				};
 
diff --git a/test/cases/parsing/typeof/index.js b/test/cases/parsing/typeof/index.js
index 93e366595ce..b8bf95b0e8d 100644
--- a/test/cases/parsing/typeof/index.js
+++ b/test/cases/parsing/typeof/index.js
@@ -29,6 +29,15 @@ it("should answer typeof require.ensure correctly", function() {
 it("should answer typeof require.resolve correctly", function() {
 	expect((typeof require.resolve)).toBe("function");
 });
+it("should answer typeof __non_webpack_require__ correctly", function() {
+	var oldValue;
+	eval("oldValue = require;");
+	expect((typeof __non_webpack_require__)).toBe("function");
+	eval("require = undefined;");
+	expect((typeof __non_webpack_require__)).toBe("undefined");
+	eval("require = oldValue;");
+	expect((typeof __non_webpack_require__)).toBe("function");
+});
 
 it("should not parse filtered stuff", function() {
 	if(typeof require != "function") require("fail");