diff --git a/Grunttasks.ts b/Grunttasks.ts
index f7a547f74..abc172e47 100644
--- a/Grunttasks.ts
+++ b/Grunttasks.ts
@@ -137,7 +137,7 @@ function getWebpackConfig(target: string, optimize: boolean = false): webpack.Co
  * @param target release, dev, or fast-dev
  */
 function getKarmaConfig(target: string, singleRun = false, browsers = ['Chrome']): karma.ConfigOptions {
-  return {
+  return <any> {
     // base path, that will be used to resolve files and exclude
     basePath: '.',
     frameworks: ['jasmine'],
@@ -149,6 +149,7 @@ function getKarmaConfig(target: string, singleRun = false, browsers = ['Chrome']
     autoWatch: true,
     browsers: browsers,
     captureTimeout: 60000,
+    concurrency: 1,
     // Avoid hardcoding and cross-origin issues.
     proxies: {
       '/': 'http://localhost:8000/'
diff --git a/src/global_require.ts b/src/global_require.ts
new file mode 100644
index 000000000..5985af87c
--- /dev/null
+++ b/src/global_require.ts
@@ -0,0 +1,13 @@
+/**
+ * The only way I could figure out how to get a handle on Node's 'require'
+ * function without confusing webpack. Using a Function constructor doesn't work,
+ * as require() isn't in its scope!
+ *
+ * Isolating in its own module so it doesn't mess up mangling in other modules.
+ */
+export default function getGlobalRequire(): Function {
+  const reqVar = eval('typeof(require)!=="undefined"?require:null');
+  return reqVar ? reqVar : function(moduleName: string): any {
+    throw new Error(`Cannot find module ${moduleName}`);
+  };
+}
\ No newline at end of file
diff --git a/src/jvm.ts b/src/jvm.ts
index 0b085ec7f..515dda452 100644
--- a/src/jvm.ts
+++ b/src/jvm.ts
@@ -18,6 +18,7 @@ import ThreadPool from './threadpool';
 import logging = require('./logging');
 import JDKInfo = require('../vendor/java_home/jdk.json');
 import global = require('./global');
+import getGlobalRequire from './global_require';
 declare var RELEASE: boolean;
 if (typeof RELEASE === 'undefined') global.RELEASE = false;
 
@@ -103,6 +104,10 @@ class JVM {
   private jitDisabled: boolean = false;
   private dumpJITStats: boolean = false;
 
+  // Get the environment's require variable, indirectly.
+  // Hidden from webpack and other builders, as it confuses them.
+  private globalRequire: Function = null;
+
   public static isReleaseBuild(): boolean {
     return typeof(RELEASE) !== 'undefined' && RELEASE;
   }
@@ -528,6 +533,9 @@ class JVM {
    */
   private evalNativeModule(mod: string): any {
     "use strict"; // Prevent eval from being terrible.
+    if (!this.globalRequire) {
+      this.globalRequire = getGlobalRequire();
+    }
     var rv: any;
     /**
      * Called by the native method file. Registers the package's native
@@ -538,10 +546,7 @@ class JVM {
     }
     // Provide the natives with the Doppio API, if needed.
     const DoppioJVM = require('./doppiojvm'),
-      globalRequire = global['require'],
-      savedRequire = typeof(globalRequire) !== 'undefined' ? globalRequire : function(moduleName: string): any {
-        throw new Error(`Cannot find module ${moduleName}`);
-      };
+      globalRequire = this.globalRequire;
 
     /**
      * An emulation of CommonJS require() for the modules.
@@ -570,9 +575,9 @@ class JVM {
         case 'pako/lib/zlib/adler32':
           return adler32;
         case 'crypto':
-          return util.are_in_browser() ? null : savedRequire('crypto');
+          return util.are_in_browser() ? null : globalRequire('crypto');
         default:
-          return savedRequire(name);
+          return globalRequire(name);
       }
     }
     /**
diff --git a/tsconfig.json b/tsconfig.json
index fa5cc5867..d328308ad 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -26,6 +26,7 @@
         "src/fd_state.ts",
         "src/gLong.ts",
         "src/global.ts",
+        "src/global_require.ts",
         "src/heap.ts",
         "src/interfaces.ts",
         "src/jar.ts",