diff --git a/src/utils.test.ts b/src/utils.test.ts
new file mode 100644
index 00000000..0f621c81
--- /dev/null
+++ b/src/utils.test.ts
@@ -0,0 +1,47 @@
+/**
+ * Copyright (c) 2018, Microsoft Corporation (MIT License).
+ */
+
+import * as assert from 'assert';
+import * as path from 'path';
+import { loadNativeModule } from './utils';
+
+const nativeName = process.platform === 'win32' ? 'conpty' : 'pty';
+
+describe('utils', () => {
+  describe('loadNativeModule', () => {
+    afterEach(() => {
+      delete process.env.NODE_PTY_PREBUILT_PATH;
+    });
+
+    it('should load from NODE_PTY_PREBUILT_PATH when set to a valid path', () => {
+      const validPath = path.resolve(__dirname, '..', 'build', 'Release');
+      process.env.NODE_PTY_PREBUILT_PATH = validPath;
+      const result = loadNativeModule(nativeName);
+      assert.strictEqual(result.dir, validPath);
+      assert.ok(result.module);
+    });
+
+    it('should fall through to default paths when NODE_PTY_PREBUILT_PATH is invalid', () => {
+      process.env.NODE_PTY_PREBUILT_PATH = '/nonexistent/path';
+      const result = loadNativeModule(nativeName);
+      assert.ok(result.dir !== '/nonexistent/path');
+      assert.ok(result.module);
+    });
+
+    it('should load normally when NODE_PTY_PREBUILT_PATH is not set', () => {
+      delete process.env.NODE_PTY_PREBUILT_PATH;
+      const result = loadNativeModule(nativeName);
+      assert.ok(result.dir);
+      assert.ok(result.module);
+    });
+
+    it('should include NODE_PTY_PREBUILT_PATH in error message when all paths fail', () => {
+      process.env.NODE_PTY_PREBUILT_PATH = '/nonexistent/path';
+      assert.throws(
+        () => loadNativeModule('does-not-exist'),
+        (err: Error) => err.message.includes('/nonexistent/path')
+      );
+    });
+  });
+});
diff --git a/src/utils.ts b/src/utils.ts
index 1d2d7c93..38683233 100644
--- a/src/utils.ts
+++ b/src/utils.ts
@@ -10,6 +10,16 @@ export function assign(target: any, ...sources: any[]): any {
 
 
 export function loadNativeModule(name: string): {dir: string, module: any} {
+  // Allow overriding the prebuilt path via environment variable
+  const envPath = process.env.NODE_PTY_PREBUILT_PATH;
+  if (envPath) {
+    try {
+      return { dir: envPath, module: require(`${envPath}/${name}.node`) };
+    } catch (e) {
+      // Fall through to default paths
+    }
+  }
+
   // Check build, debug, and then prebuilds.
   const dirs = ['build/Release', 'build/Debug', `prebuilds/${process.platform}-${process.arch}`];
   // Check relative to the parent dir for unbundled and then the current dir for bundled
@@ -25,5 +35,5 @@ export function loadNativeModule(name: string): {dir: string, module: any} {
       }
     }
   }
-  throw new Error(`Failed to load native module: ${name}.node, checked: ${dirs.join(', ')}: ${lastError}`);
+  throw new Error(`Failed to load native module: ${name}.node, checked: ${envPath ? envPath + ', ' : ''}${dirs.join(', ')}: ${lastError}`);
 }