diff --git a/.vscode/launch.json b/.vscode/launch.json
index 573753853bb5e..fa27febeea023 100644
--- a/.vscode/launch.json
+++ b/.vscode/launch.json
@@ -108,11 +108,11 @@
             "name": "Run Mocha Test",
             "program": "${workspaceRoot}/node_modules/mocha/bin/_mocha",
             "args": [
-                "${file}",
                 "--no-timeouts",
                 "--colors",
                 "--opts",
-                "${workspaceRoot}/configs/mocha.opts"
+                "${workspaceRoot}/configs/mocha.opts",
+                "**/${fileBasenameNoExtension}.js"
             ],
             "env": {
                 "TS_NODE_PROJECT": "${workspaceRoot}/tsconfig.json"
diff --git a/configs/mocha.opts b/configs/mocha.opts
index b487035eec14f..ef23a43a792c7 100644
--- a/configs/mocha.opts
+++ b/configs/mocha.opts
@@ -1,6 +1,5 @@
 --require ignore-styles
 --require monaco-languageclient/lib/register-vscode
---require ts-node/register
 --require reflect-metadata/Reflect
 --reporter spec
---watch-extensions ts
\ No newline at end of file
+--watch-extensions js
diff --git a/dev-packages/ext-scripts/package.json b/dev-packages/ext-scripts/package.json
index 28bda586f7197..1e70fcfe3263e 100644
--- a/dev-packages/ext-scripts/package.json
+++ b/dev-packages/ext-scripts/package.json
@@ -25,8 +25,8 @@
     "ext:watch": "tsc -w -p compile.tsconfig.json",
     "ext:docs": "typedoc --tsconfig ../../configs/typedoc-tsconfig.json --options ../../configs/typedoc.json src",
     "ext:docs:clean": "rimraf docs/api",
-    "ext:test": "nyc mocha --opts ../../configs/mocha.opts \"./src/**/*.*spec.ts\"",
-    "ext:test:watch": "mocha -w --opts ../../configs/mocha.opts \"./src/**/*.*spec.ts\"",
+    "ext:test": "nyc mocha --opts ../../configs/mocha.opts \"./lib/**/*.*spec.js\"",
+    "ext:test:watch": "mocha -w --opts ../../configs/mocha.opts \"./lib/**/*.*spec.js\"",
     "ext:test:clean": "rimraf .nyc_output && rimraf coverage"
   }
 }
diff --git a/doc/Testing.md b/doc/Testing.md
index f5706b42988b4..571ccd0502386 100644
--- a/doc/Testing.md
+++ b/doc/Testing.md
@@ -2,6 +2,8 @@
 
 ## Running tests
 
+Before running make sure to compile tests with `compile` or `watch` scripts.
+
 To run tests on theia run:
 
 `yarn test`
@@ -12,6 +14,7 @@ If you want to run all tests for a particular Theia extension, execute the follo
 
 `npx run test @theia/extension-name`
 
+
 Add the following npm script to the `package.json` of the desired Theia extension, if you would like to enable the watch mode for the tests.
 
 ```json
diff --git a/packages/keymaps/compile.tsconfig.json b/packages/keymaps/compile.tsconfig.json
index 91ea1015832d3..a23513b5e6b13 100644
--- a/packages/keymaps/compile.tsconfig.json
+++ b/packages/keymaps/compile.tsconfig.json
@@ -6,8 +6,5 @@
   },
   "include": [
     "src"
-  ],
-  "exclude": [
-    "**/*.spec.ts"
   ]
-}
\ No newline at end of file
+}
diff --git a/packages/process/src/node/raw-process.spec.ts b/packages/process/src/node/raw-process.spec.ts
index 3bc6282872fe8..e9d9aab7e89ef 100644
--- a/packages/process/src/node/raw-process.spec.ts
+++ b/packages/process/src/node/raw-process.spec.ts
@@ -31,7 +31,7 @@ const track = temp.track();
  */
 
 const expect = chai.expect;
-const FORK_TEST_FILE = path.join(__dirname, 'test', 'process-fork-test.js');
+const FORK_TEST_FILE = path.join(__dirname, '../../src/node/test/process-fork-test.js');
 
 describe('RawProcess', function () {