diff --git a/tests/Mutator/Removal/ArrayItemRemovalTest.php b/tests/Mutator/Removal/ArrayItemRemovalTest.php
index 32d4d0d67..49d7f06f5 100644
--- a/tests/Mutator/Removal/ArrayItemRemovalTest.php
+++ b/tests/Mutator/Removal/ArrayItemRemovalTest.php
@@ -31,6 +31,8 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
+declare(strict_types=1);
+
 namespace Infection\Tests\Mutator\Removal;
 
 use Generator;