diff --git a/src/register.ts b/src/register.ts
index 5d85605..f668ec8 100644
--- a/src/register.ts
+++ b/src/register.ts
@@ -2,47 +2,6 @@ import { createMatchPath } from "./match-path-sync";
 import { configLoader, ExplicitParams } from "./config-loader";
 import { options } from "./options";
 
-function getCoreModules(
-  builtinModules: string[] | undefined
-): { [key: string]: boolean } {
-  builtinModules = builtinModules || [
-    "assert",
-    "buffer",
-    "child_process",
-    "cluster",
-    "crypto",
-    "dgram",
-    "dns",
-    "domain",
-    "events",
-    "fs",
-    "http",
-    "https",
-    "net",
-    "os",
-    "path",
-    "punycode",
-    "querystring",
-    "readline",
-    "stream",
-    "string_decoder",
-    "tls",
-    "tty",
-    "url",
-    "util",
-    "v8",
-    "vm",
-    "zlib"
-  ];
-
-  const coreModules: { [key: string]: boolean } = {};
-  for (let module of builtinModules) {
-    coreModules[module] = true;
-  }
-
-  return coreModules;
-}
-
 /**
  * Installs a custom module load function that can adhere to paths in tsconfig.
  */
@@ -68,19 +27,21 @@ export function register(explicitParams: ExplicitParams): void {
   // tslint:disable-next-line:no-require-imports variable-name
   const Module = require("module");
   const originalResolveFilename = Module._resolveFilename;
-  const coreModules = getCoreModules(Module.builtinModules);
+
   // tslint:disable-next-line:no-any
   Module._resolveFilename = function(request: string, _parent: any): string {
-    const isCoreModule = coreModules.hasOwnProperty(request);
-    if (!isCoreModule) {
+    try {
+      // tslint:disable-next-line:no-invalid-this
+      return originalResolveFilename.apply(this, arguments);
+    } catch (err) {
       const found = matchPath(request);
       if (found) {
         const modifiedArguments = [found, ...[].slice.call(arguments, 1)]; // Passes all arguments. Even those that is not specified above.
         // tslint:disable-next-line:no-invalid-this
         return originalResolveFilename.apply(this, modifiedArguments);
       }
+
+      throw err;
     }
-    // tslint:disable-next-line:no-invalid-this
-    return originalResolveFilename.apply(this, arguments);
   };
 }