diff --git a/docs/docs/10-reference.md b/docs/docs/10-reference.md
index 6ea524f633..fc41d81814 100644
--- a/docs/docs/10-reference.md
+++ b/docs/docs/10-reference.md
@@ -109,6 +109,8 @@ Options:
   - Configure your dev server. See the section below for all options.
 - **`buildOptions.*`**
   - Configure your build. See the section below for all options.
+- **`testOptions.*`**
+  - Configure your tests. See the section below for all options.
 
 #### `config.installOptions`
 
@@ -223,6 +225,26 @@ Options:
 - **`buildOptions.webModulesUrl`** | `string` | Default: `web_modules`
   - Rename your web modules directory.
 
+#### `config.testOptions`
+
+`object` (options)
+
+Settings that determine how the Snowpack test environment behaves.
+
+Example:
+
+```js
+testOptions: {
+  files: ['my-test-dir/*.test.js'];
+}
+```
+
+Options:
+
+- **`testOptions.files`** | `string[]` | Default: `["__tests__/**/*", "**/*.@(spec|test).*"]`
+  - The location of all test files.
+  - All matching test files are scanned for installable dependencies during development, but excluded from both scanning and building in your final build.
+
 #### `config.proxy`
 
 `object` (path: options)
diff --git a/snowpack/src/commands/build.ts b/snowpack/src/commands/build.ts
index 0babcdb3d3..bf8ee03962 100644
--- a/snowpack/src/commands/build.ts
+++ b/snowpack/src/commands/build.ts
@@ -372,7 +372,7 @@ export async function command(commandOptions: CommandOptions) {
   // 0. Find all source files.
   for (const [mountedDir, mountEntry] of Object.entries(config.mount)) {
     const allFiles = glob.sync(`**/*`, {
-      ignore: config.exclude,
+      ignore: [...config.exclude, ...config.testOptions.files],
       cwd: mountedDir,
       absolute: true,
       nodir: true,
diff --git a/snowpack/src/commands/install.ts b/snowpack/src/commands/install.ts
index d5ac897202..dd1af50a38 100644
--- a/snowpack/src/commands/install.ts
+++ b/snowpack/src/commands/install.ts
@@ -27,7 +27,7 @@ export async function getInstallTargets(
   if (scannedFiles) {
     installTargets.push(...(await scanImportsFromFiles(scannedFiles, config)));
   } else {
-    installTargets.push(...(await scanImports(config)));
+    installTargets.push(...(await scanImports(process.env.NODE_ENV === 'test', config)));
   }
   return installTargets;
 }
diff --git a/snowpack/src/config.ts b/snowpack/src/config.ts
index c348360e71..5524b63c54 100644
--- a/snowpack/src/config.ts
+++ b/snowpack/src/config.ts
@@ -31,14 +31,14 @@ import {
 } from './util';
 
 const CONFIG_NAME = 'snowpack';
-const ALWAYS_EXCLUDE = ['**/node_modules/**/*', '**/.types/**/*'];
+const ALWAYS_EXCLUDE = ['**/node_modules/**/*', '**/web_modules/**/*', '**/.types/**/*'];
 
 // default settings
 const DEFAULT_CONFIG: Partial<SnowpackConfig> = {
-  exclude: ['__tests__/**/*', '**/*.@(spec|test).*'],
   plugins: [],
   alias: {},
   scripts: {},
+  exclude: [],
   installOptions: {},
   devOptions: {
     secure: false,
@@ -61,6 +61,9 @@ const DEFAULT_CONFIG: Partial<SnowpackConfig> = {
     sourceMaps: false,
     watch: false,
   },
+  testOptions: {
+    files: ['__tests__/**/*', '**/*.@(spec|test).*'],
+  },
   experiments: {
     ssr: false,
   },
@@ -149,6 +152,12 @@ const configSchema = {
         ssr: {type: 'boolean'},
       },
     },
+    testOptions: {
+      type: 'object',
+      properties: {
+        files: {type: 'array', items: {type: 'string'}},
+      },
+    },
     experiments: {
       type: ['object'],
       properties: {
diff --git a/snowpack/src/scan-imports.ts b/snowpack/src/scan-imports.ts
index 5da6a31ff5..f4ee2f63f3 100644
--- a/snowpack/src/scan-imports.ts
+++ b/snowpack/src/scan-imports.ts
@@ -226,12 +226,16 @@ export function scanDepList(depList: string[], cwd: string): InstallTarget[] {
     .reduce((flat, item) => flat.concat(item), []);
 }
 
-export async function scanImports(config: SnowpackConfig): Promise<InstallTarget[]> {
+export async function scanImports(
+  includeTests: boolean,
+  config: SnowpackConfig,
+): Promise<InstallTarget[]> {
   await initESModuleLexer;
+  const ignore = includeTests ? config.exclude : [...config.exclude, ...config.testOptions.files];
   const includeFileSets = await Promise.all(
     Object.keys(config.mount).map((fromDisk) => {
       return glob.sync(`**/*`, {
-        ignore: config.exclude.concat(['**/web_modules/**/*']),
+        ignore,
         cwd: fromDisk,
         absolute: true,
         nodir: true,
diff --git a/snowpack/src/types/snowpack.ts b/snowpack/src/types/snowpack.ts
index 638b7a22f6..82303d05f0 100644
--- a/snowpack/src/types/snowpack.ts
+++ b/snowpack/src/types/snowpack.ts
@@ -150,6 +150,9 @@ export interface SnowpackConfig {
     sourceMaps: boolean;
     watch: boolean;
   };
+  testOptions: {
+    files: string[];
+  };
   /** EXPERIMENTAL - This section is experimental and not yet finalized. May change across minor versions. */
   experiments: {
     /** (EXPERIMENTAL) If true, "snowpack build" should build your site for SSR. */