1 files changed, 2 insertions, 0 deletions
diff --git a/lib/os.js b/lib/os.js
index 9fc4673771..cace46173b 100644
--- a/lib/os.js
+++ b/lib/os.js
@@ -19,6 +19,8 @@
 // OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
 // USE OR OTHER DEALINGS IN THE SOFTWARE.
 
+'use strict';
+
 var binding = process.binding('os');
 var util = require('util');
 var isWindows = process.platform === 'win32';