diff --git a/.github/SAMPLE_GUIDELINE.md b/.github/SAMPLE_GUIDELINE.md
index da3a02c2..d497b88a 100644
--- a/.github/SAMPLE_GUIDELINE.md
+++ b/.github/SAMPLE_GUIDELINE.md
@@ -33,6 +33,7 @@ Only deviate from the standard setting if your sample needs to.
 - 5.1: Include a `.prettier.json` following https://github.com/Microsoft/vscode-extension-samples/blob/ext-docs/hellocode-sample/.prettierrc.json.
 - 5.2: Include a `tslint.json` following https://github.com/Microsoft/vscode-extension-samples/blob/ext-docs/hellocode-sample/tslint.json.
 - 5.3: Include a `tsconfig.json` following https://github.com/Microsoft/vscode-extension-samples/blob/ext-docs/hellocode-sample/tsconfig.json.
+- 5.4: Your source code should be formatted using the formatter and contain no TSLint/TS errors.
 
 ## 6: Tests