diff --git a/test/smoke/src/main.ts b/test/smoke/src/main.ts
index 5ffd62c3ed4..a45b784cbf9 100644
--- a/test/smoke/src/main.ts
+++ b/test/smoke/src/main.ts
@@ -77,7 +77,7 @@ process.env.SCREENSHOTS_DIR = path.join(testDataPath, 'screenshots-dir');
 process.env.SMOKETEST_REPO = testRepoLocalDir;
 process.env.VSCODE_WORKSPACE_PATH = workspacePath;
 process.env.VSCODE_KEYBINDINGS_PATH = keybindingsPath;
-process.env.CAPTURE_SCREENSHOT = Object.keys(opts).indexOf('screenshot') ? 'screenshot' : '';
+process.env.CAPTURE_SCREENSHOT = Object.keys(opts).indexOf('screenshot') !== -1 ? 'screenshot' : '';
 
 if (process.env.VSCODE_DEV === '1') {
 	process.env.VSCODE_EDITION = 'dev';