diff --git a/packages/cli/package.json b/packages/cli/package.json
index 52b4d23aa2..623b042142 100644
--- a/packages/cli/package.json
+++ b/packages/cli/package.json
@@ -68,7 +68,8 @@
     "tar": "^6.0.1",
     "ts-loader": "^7.0.4",
     "webpack": "^4.41.6",
-    "webpack-dev-server": "^3.10.3"
+    "webpack-dev-server": "^3.10.3",
+    "yn": "^4.0.0"
   },
   "devDependencies": {
     "@types/diff": "^4.0.2",
diff --git a/packages/cli/src/lib/bundle/server.ts b/packages/cli/src/lib/bundle/server.ts
index 2dcd3b3a8a..333db1394e 100644
--- a/packages/cli/src/lib/bundle/server.ts
+++ b/packages/cli/src/lib/bundle/server.ts
@@ -14,6 +14,7 @@
  * limitations under the License.
  */
 
+import yn from 'yn';
 import webpack from 'webpack';
 import WebpackDevServer from 'webpack-dev-server';
 import openBrowser from 'react-dev-utils/openBrowser';
@@ -30,7 +31,7 @@ export async function startDevServer() {
     return;
   }
 
-  const protocol = process.env.HTTPS === 'true' ? 'https' : 'http';
+  const protocol = yn(process.env.HTTPS, { default: false }) ? 'https' : 'http';
   const urls = prepareUrls(protocol, host, port);
 
   const paths = resolveBundlingPaths();