1 files changed, 2 insertions, 0 deletions
diff --git a/lib/freelist.js b/lib/freelist.js
index 588facd25b..561ca53458 100644
--- a/lib/freelist.js
+++ b/lib/freelist.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';
+
 // This is a free list to avoid creating so many of the same object.
 exports.FreeList = function(name, max, constructor) {
   this.name = name;