diff --git a/utils/examples/extract.tcl b/utils/examples/extract.tcl
index a596111..dc62a06 100644
--- a/utils/examples/extract.tcl
+++ b/utils/examples/extract.tcl
@@ -11,6 +11,7 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+# SPDX-License-Identifier: Apache-2.0
 
 lef read $::env(PDKPATH)/libs.ref/techLEF/scs8hd/scs8hd_tech.lef
 set macro_mags "openram_tc_core.mag"