diff --git a/extensions/package.json b/extensions/package.json
index a8e81d5a82..3d46e23372 100644
--- a/extensions/package.json
+++ b/extensions/package.json
@@ -39,5 +39,8 @@
     "prettier": "2.0.5",
     "typescript": "^4.0.5",
     "validate-npm-package-name": "4.0.0"
+  },
+  "devDependencies": {
+    "cross-env": "7.0.3"
   }
 }
diff --git a/extensions/scripts/build.js b/extensions/scripts/build.js
index 55fe6ef653..fba609b284 100644
--- a/extensions/scripts/build.js
+++ b/extensions/scripts/build.js
@@ -6,6 +6,41 @@ const path = require('path');
 const fs = require('fs-extra');
 const esbuild = require('esbuild');
 const GlobalsPlugin = require('esbuild-plugin-globals');
+const ts = require('typescript');
+
+const formatHost = {
+  getCanonicalFileName: (path) => path,
+  getCurrentDirectory: ts.sys.getCurrentDirectory,
+  getNewLine: () => ts.sys.newLine,
+};
+
+function typecheck(extPath) {
+  return new Promise((resolve, reject) => {
+    const tsConfigPath = ts.findConfigFile(extPath, ts.sys.fileExists, 'tsconfig.json');
+
+    if (tsConfigPath) {
+      // eslint-disable-next-line security/detect-non-literal-fs-filename
+      const configFile = ts.readJsonConfigFile(tsConfigPath, ts.sys.readFile);
+
+      const { fileNames, options } = ts.parseJsonSourceFileConfigFileContent(configFile, ts.sys, extPath);
+
+      const program = ts.createProgram(fileNames, { ...options, noEmit: true });
+      const emitResult = program.emit();
+
+      const allDiagnostics = ts.getPreEmitDiagnostics(program).concat(emitResult.diagnostics);
+      const hasTsErrors = allDiagnostics.some((d) => d.category === ts.DiagnosticCategory.Error);
+
+      if (hasTsErrors) {
+        const tsOutput = ts.formatDiagnosticsWithColorAndContext(allDiagnostics, formatHost);
+
+        reject(new Error(`TypeScript errors:\n${tsOutput}}`));
+        return;
+      }
+    }
+
+    resolve();
+  });
+}
 
 const getBundleConfigs = (extPath, packageJSON, watch = false) => {
   const buildConfigs = [];
@@ -111,6 +146,7 @@ const compile = async (name, extPath, watch = false) => {
 
   try {
     await cleanDist(name, extPath);
+    work.push(typecheck(extPath));
     for (const config of getBundleConfigs(extPath, packageJSON, watch)) {
       work.push(service.build(config));
     }
diff --git a/extensions/yarn-berry.lock b/extensions/yarn-berry.lock
index 280095eb7b..2e08db61bd 100644
--- a/extensions/yarn-berry.lock
+++ b/extensions/yarn-berry.lock
@@ -534,6 +534,7 @@ __metadata:
     "@types/fs-extra": 9.0.13
     "@typescript-eslint/eslint-plugin": 2.34.0
     "@typescript-eslint/parser": 2.34.0
+    cross-env: 7.0.3
     esbuild: ^0.8.44
     esbuild-plugin-globals: 0.1.1
     eslint: 7.0.0
@@ -580,7 +581,19 @@ __metadata:
   languageName: node
   linkType: hard
 
-"cross-spawn@npm:^7.0.2":
+"cross-env@npm:7.0.3":
+  version: 7.0.3
+  resolution: "cross-env@npm:7.0.3"
+  dependencies:
+    cross-spawn: ^7.0.1
+  bin:
+    cross-env: src/bin/cross-env.js
+    cross-env-shell: src/bin/cross-env-shell.js
+  checksum: 26f2f3ea2ab32617f57effb70d329c2070d2f5630adc800985d8b30b56e8bf7f5f439dd3a0358b79cee6f930afc23cf8e23515f17ccfb30092c6b62c6b630a79
+  languageName: node
+  linkType: hard
+
+"cross-spawn@npm:^7.0.1, cross-spawn@npm:^7.0.2":
   version: 7.0.3
   resolution: "cross-spawn@npm:7.0.3"
   dependencies: