diff --git a/README.md b/README.md
index 60f59a6..6f55e96 100644
--- a/README.md
+++ b/README.md
@@ -40,7 +40,7 @@ In your `package.json` add a new script:
 "scripts" :{
   ...
   "cy:run": "cypress run", // It can be any cypress command with any argument
-  "cy:parallel" : "cypress-parallel -s cy:run -t 2 -d '<your-cypress-specs-folder>' -a '\"<your-cypress-cmd-args>\"'"
+  "cy:parallel" : "cypress-parallel -s cy:run -t 2 --spec '<your-cypress-specs-folder(s)-or-file(s)>' -a '\"<your-cypress-cmd-args>\"'"
   ...
 }
 ```
@@ -64,33 +64,32 @@ or
 Run with npx (no package installation needed)
 
 ```
-npx cy:parallel -s cy:run -t 2 -d '<your-cypress-specs-folder>' -a '"<your-cypress-cmd-args>"'
+npx cy:parallel -s cy:run -t 2 --spec '<your-cypress-specs-folder(s)-or-file(s)>' -a '"<your-cypress-cmd-args>"'
 ```
 
-## Passing Specs
+## Passing Multiple Specs
 
 ```
-cypress-parallel -s cy:run -t 2 -a '\"<your-cypress-cmd-args>\"' --spec path/to/spec1.spec.js path/to/spec2.spec.js
+cypress-parallel -s cy:run -t 2 -a '\"<your-cypress-cmd-args>\"' --spec path/to/spec1.spec.js path/to/spec2.spec.js path/to/more/specs/**/*.js
 ```
 
 ### Scripts options
 
-| Option            | Alias | Description                        | Type   |
-| ----------------- | ----- | ---------------------------------- | ------ |
-| --help            |       | Show help                          |        |
-| --version         |       | Show version number                |        |
-| --script          | -s    | Your npm Cypress command           | string |
-| --args            | -a    | Your npm Cypress command arguments | string |
-| --threads         | -t    | Number of threads                  | number |
-| --specsDir        | -d    | Cypress specs directory            | string |
-| --spec            |       | Cypress spec file paths            | string |
-| --weightsJson     | -w    | Parallel weights json file         | string |
-| --reporter        | -r    | Reporter to pass to Cypress.       | string |
-| --reporterOptions | -o    | Reporter options                   | string |
-| --reporterModulePath | -n    | Specify the reporter module path   | string |
-| --bail            | -b    | Exit on first failing thread       | string |
-| --verbose         | -v    | Some additional logging            | string |
-| --strictMode      | -m    | Add stricter checks after running the tests           | boolean |
+| Option               | Alias | Description                                                           | Type    |
+| -------------------- | ----- | --------------------------------------------------------------------- | ------- |
+| --help               |       | Show help                                                             |         |
+| --version            |       | Show version number                                                   |         |
+| --script             | -s    | Your npm Cypress command                                              | string  |
+| --args               | -a    | Your npm Cypress command arguments                                    | string  |
+| --threads            | -t    | Number of threads                                                     | number  |
+| --spec               | -d    | Cypress spec file path(s), or glob pattern(s). Can be one, or a list. | string  |
+| --weightsJson        | -w    | Parallel weights json file                                            | string  |
+| --reporter           | -r    | Reporter to pass to Cypress.                                          | string  |
+| --reporterOptions    | -o    | Reporter options                                                      | string  |
+| --reporterModulePath | -n    | Specify the reporter module path                                      | string  |
+| --bail               | -b    | Exit on first failing thread                                          | string  |
+| --verbose            | -v    | Some additional logging                                               | string  |
+| --strictMode         | -m    | Add stricter checks after running the tests                           | boolean |
 
 **NB**: If you use *cypress-cucumber-preprocesor*, please **disable** the *strictMode* to avoid possible errors:
 
diff --git a/lib/README.md b/lib/README.md
index 823a107..6f55e96 100644
--- a/lib/README.md
+++ b/lib/README.md
@@ -23,13 +23,13 @@ Reduce up to 40% your Cypress suite execution time parallelizing the test run on
 ## Install
 
 ```
-npm i cypress-parallel
+npm i cypress-parallel -D
 ```
 
 or
 
 ```
-yarn add cypress-parallel
+yarn add cypress-parallel -D
 ```
 
 ## Add a new script
@@ -40,7 +40,7 @@ In your `package.json` add a new script:
 "scripts" :{
   ...
   "cy:run": "cypress run", // It can be any cypress command with any argument
-  "cy:parallel" : "cypress-parallel -s cy:run -t 2 -d <your-cypress-specs-folder> -a '\"<your-cypress-cmd-args>\"'"
+  "cy:parallel" : "cypress-parallel -s cy:run -t 2 --spec '<your-cypress-specs-folder(s)-or-file(s)>' -a '\"<your-cypress-cmd-args>\"'"
   ...
 }
 ```
@@ -64,26 +64,32 @@ or
 Run with npx (no package installation needed)
 
 ```
-npx cy:parallel -s cy:run -t 2 -d <your-cypress-specs-folder> -a '\"<your-cypress-cmd-args>\"'
+npx cy:parallel -s cy:run -t 2 --spec '<your-cypress-specs-folder(s)-or-file(s)>' -a '"<your-cypress-cmd-args>"'
+```
+
+## Passing Multiple Specs
+
+```
+cypress-parallel -s cy:run -t 2 -a '\"<your-cypress-cmd-args>\"' --spec path/to/spec1.spec.js path/to/spec2.spec.js path/to/more/specs/**/*.js
 ```
 
 ### Scripts options
 
-| Option            | Alias | Description                        | Type   |
-| ----------------- | ----- | ---------------------------------- | ------ |
-| --help            |       | Show help                          |        |
-| --version         |       | Show version number                |        |
-| --script          | -s    | Your npm Cypress command           | string |
-| --args            | -a    | Your npm Cypress command arguments | string |
-| --threads         | -t    | Number of threads                  | number |
-| --specsDir        | -d    | Cypress specs directory            | string |
-| --weightsJson     | -w    | Parallel weights json file         | string |
-| --reporter        | -r    | Reporter to pass to Cypress.       | string |
-| --reporterOptions | -o    | Reporter options                   | string |
-| --reporterModulePath | -n    | Specify the reporter module path   | string |
-| --bail            | -b    | Exit on first failing thread       | string |
-| --verbose         | -v    | Some additional logging            | string |
-| --strictMode      | -m    | Add stricter checks after running the tests           | boolean |
+| Option               | Alias | Description                                                           | Type    |
+| -------------------- | ----- | --------------------------------------------------------------------- | ------- |
+| --help               |       | Show help                                                             |         |
+| --version            |       | Show version number                                                   |         |
+| --script             | -s    | Your npm Cypress command                                              | string  |
+| --args               | -a    | Your npm Cypress command arguments                                    | string  |
+| --threads            | -t    | Number of threads                                                     | number  |
+| --spec               | -d    | Cypress spec file path(s), or glob pattern(s). Can be one, or a list. | string  |
+| --weightsJson        | -w    | Parallel weights json file                                            | string  |
+| --reporter           | -r    | Reporter to pass to Cypress.                                          | string  |
+| --reporterOptions    | -o    | Reporter options                                                      | string  |
+| --reporterModulePath | -n    | Specify the reporter module path                                      | string  |
+| --bail               | -b    | Exit on first failing thread                                          | string  |
+| --verbose            | -v    | Some additional logging                                               | string  |
+| --strictMode         | -m    | Add stricter checks after running the tests                           | boolean |
 
 **NB**: If you use *cypress-cucumber-preprocesor*, please **disable** the *strictMode* to avoid possible errors:
 
@@ -105,10 +111,21 @@ npx cy:parallel -s cy:run -t 2 -d <your-cypress-specs-folder> -a '\"<your-cypres
 }
 ```
 
+## Env variables
+
+### CYPRESS_THREAD
+
+You can get the current thread index by reading the `CYPRESS_THREAD` variable.
+
+```javascript
+ const threadIndex = process.env.CYPRESS_THREAD;
+ // return 1, 2, 3, 4, ...
+```
+
 # Contributors
 
 Looking for contributors.
 
 # License
 
-MIT
+This project is licensed under the MIT license. See [LICENSE](LICENSE).
diff --git a/lib/cli.js b/lib/cli.js
index f616e8c..47ed81f 100755
--- a/lib/cli.js
+++ b/lib/cli.js
@@ -6,7 +6,7 @@ const path = require('path');
 const fs = require('fs-extra');
 const { settings } = require('./settings');
 
-const { getTestSuitePaths, distributeTestsByWeight, getMaxPathLenghtFrom } = require('./test-suites');
+const { getTestSuitePaths, distributeTestsByWeight, getMaxPathLengthFrom } = require('./test-suites');
 const {
   formatTime,
   generateWeightsFile,
@@ -55,7 +55,7 @@ async function start() {
   let table = new Table({
     head: ['Spec', 'Time', 'Tests', 'Passing', 'Failing', 'Pending'],
     style: { head: ['blue'] },
-    colWidths: [getMaxPathLenghtFrom(testSuitePaths), 10, 10, 10, 10, 10]
+    colWidths: [getMaxPathLengthFrom(testSuitePaths), 10, 10, 10, 10, 10]
   });
 
   let totalTests = 0;
diff --git a/lib/settings.js b/lib/settings.js
index c3e5954..cb3d7c6 100644
--- a/lib/settings.js
+++ b/lib/settings.js
@@ -22,14 +22,11 @@ const argv = yargs
     type: 'boolean',
     description: 'Exit on first suite finishing with errors'
   })
-  .option('specsDir', {
-    alias: 'd',
-    type: 'string',
-    description: 'Cypress specs directory'
-  })
   .option('spec', {
+    alias: ['specsDir', 'd'], // include specDir and -d so that is non-breaking. In future version, can remove.
     type: 'array',
-    description: 'List of Cypress spec paths'
+    description: 'Cypress spec path(s), or glob pattern(s). Can be one, or a list.',
+    default: ['cypress/integration/**/*']
   })
   .option('args', {
     alias: 'a',
@@ -83,10 +80,24 @@ const COLORS = [
   '\x1b[40m'
 ];
 
+/** @type {{
+    threadCount: number
+    testSuitesPaths: string[]
+    shouldBail: boolean
+    isVerbose: boolean
+    weightsJSON: string
+    defaultWeight: number
+    reporter?: string
+    reporterModulePath: string
+    reporterOptions?: string
+    reporterOptionsPath?: string
+    script: string
+    strictMode: boolean
+    scriptArguments: string[]
+ }} */
 const settings = {
   threadCount: argv.threads ? argv.threads : 2,
-  testSuitesPath: argv.specsDir ? argv.specsDir : 'cypress/integration',
-  testSuitesPaths: argv.spec ? argv.spec : undefined,
+  testSuitesPaths: argv.spec,
   shouldBail: argv.bail ? argv.bail : false,
   isVerbose: argv.verbose ? argv.verbose : false,
   weightsJSON: argv.weightsJson
diff --git a/lib/test-suites.js b/lib/test-suites.js
index 4bdb2fc..1dc2fa5 100644
--- a/lib/test-suites.js
+++ b/lib/test-suites.js
@@ -4,28 +4,28 @@ const { glob } = require('glob');
 
 const { settings } = require('./settings');
 
-const getFilePathsByPath = (dir) =>
-  fs.readdirSync(dir).reduce((files, file) => {
-    const name = path.join(dir, file);
-    const isDirectory = fs.statSync(name).isDirectory();
-    if (isDirectory) return [...files, ...getFilePathsByPath(name)];
-    return [...files, name];
-  }, []);
-
 async function getTestSuitePaths() {
-  const isPattern = settings.testSuitesPath.includes('*');
-
-  let fileList;
-  if (settings.testSuitesPaths) {
-    fileList = settings.testSuitesPaths;
-  } else if (isPattern) {
-    console.log(`Using pattern ${settings.testSuitesPath} to find test suites`);
-    fileList = await glob(settings.testSuitesPath, { ignore: 'node_modules/**' });
-  } else {
-    console.log(
-      'DEPRECATED: using path is deprecated and will be removed, switch to glob pattern'
-    );
-    fileList = getFilePathsByPath(settings.testSuitesPath);
+  let fileList = [];
+  for (const suitePath of settings.testSuitesPaths) {
+    let globPattern = undefined
+    if (suitePath.includes('*')) {
+      globPattern = suitePath
+    } else if (fs.existsSync(suitePath) && fs.lstatSync(suitePath).isDirectory()) {
+      console.log(
+        'DEPRECATED: using directory path is deprecated and will be removed, switch to glob pattern'
+      );
+      globPattern = `${suitePath}/**/*`
+    }
+
+    if (globPattern) {
+      if (settings.isVerbose) {
+        console.log(`Using pattern ${globPattern} to find test suites`);
+      }
+      const thisFileList = await glob(globPattern, { ignore: 'node_modules/**' })
+      fileList.concat(thisFileList);
+    } else {
+      fileList.append(suitePath)
+    }
   }
 
   console.log(`${fileList.length} test suite(s) found.`);
@@ -36,19 +36,21 @@ async function getTestSuitePaths() {
 
   // We can't run more threads than suites
   if (fileList.length < settings.threadCount) {
-    console.log(
-      `Thread setting is ${settings.threadCount}, but only ${fileList.length} test suite(s) were found. Adjusting configuration accordingly.`
-    );
+    if (settings.isVerbose) {
+      console.log(
+        `Thread setting is ${settings.threadCount}, but only ${fileList.length} test suite(s) were found. Adjusting configuration accordingly.`
+      );
+    }
     settings.threadCount = fileList.length;
   }
 
   return fileList;
 }
 
-function getMaxPathLenghtFrom(testSuitePaths) {
+function getMaxPathLengthFrom(testSuitePaths) {
   let maxLength = 10;
 
-  for(let path of testSuitePaths){
+  for (let path of testSuitePaths) {
     maxLength = Math.max(maxLength, path.length);
   }
 
@@ -99,5 +101,5 @@ function distributeTestsByWeight(testSuitePaths) {
 module.exports = {
   getTestSuitePaths,
   distributeTestsByWeight,
-  getMaxPathLenghtFrom
+  getMaxPathLengthFrom
 };