diff --git a/baremaps-renderer/assets/report-template.html b/baremaps-renderer/assets/report-template.html
index a29ae9a74..3a4395e09 100644
--- a/baremaps-renderer/assets/report-template.html
+++ b/baremaps-renderer/assets/report-template.html
@@ -15,7 +15,7 @@
 limitations under the License.
 -->
 <!DOCTYPE html>
-<html>
+<html lang="en">
   <head>
     <title>Baremaps Renderer</title>
     <style>
diff --git a/baremaps-server/src/main/resources/geocoder/index.html b/baremaps-server/src/main/resources/geocoder/index.html
index c97cdb60b..5ae75f292 100644
--- a/baremaps-server/src/main/resources/geocoder/index.html
+++ b/baremaps-server/src/main/resources/geocoder/index.html
@@ -15,7 +15,7 @@
 See the License for the specific language governing permissions and
 limitations under the License.
 -->
-<html>
+<html lang="en">
 <head>
     <meta charset="utf-8"/>
     <title>Baremaps Geocoder example</title>
diff --git a/baremaps-server/src/main/resources/iploc/index.html b/baremaps-server/src/main/resources/iploc/index.html
index 8e84017f0..3d7d38ec6 100644
--- a/baremaps-server/src/main/resources/iploc/index.html
+++ b/baremaps-server/src/main/resources/iploc/index.html
@@ -15,7 +15,7 @@
 See the License for the specific language governing permissions and
 limitations under the License.
 -->
-<html>
+<html lang="en">
 <head>
     <meta charset="utf-8"/>
     <title>Baremaps Iploc example</title>
diff --git a/baremaps-server/src/main/resources/static/server.html b/baremaps-server/src/main/resources/static/server.html
index b1fc66e0c..d5ef77521 100644
--- a/baremaps-server/src/main/resources/static/server.html
+++ b/baremaps-server/src/main/resources/static/server.html
@@ -15,7 +15,7 @@
 See the License for the specific language governing permissions and
 limitations under the License.
 -->
-<html>
+<html lang="en">
 <head>
   <script src="https://unpkg.com/maplibre-gl@4.0.2/dist/maplibre-gl.js" integrity="sha256-qmQe97oAYERiVjChfXOO7hB6XvtPv+LURdheDkwjygk=" crossorigin="anonymous"></script>
   <script src="https://baremaps.apache.org/assets/maplibre/maplibre-gl-inspect.js" integrity="sha256-NYdRoIbqeAWkTHjpa/BukMLXcsiqFoDuJCYzzaRei30=" crossorigin="anonymous"></script>
diff --git a/baremaps-server/src/main/resources/static/viewer.html b/baremaps-server/src/main/resources/static/viewer.html
index c5a920de3..75b3b773a 100644
--- a/baremaps-server/src/main/resources/static/viewer.html
+++ b/baremaps-server/src/main/resources/static/viewer.html
@@ -15,7 +15,7 @@
 See the License for the specific language governing permissions and
 limitations under the License.
 -->
-<html>
+<html lang="en">
 <head>
   <script src="https://unpkg.com/maplibre-gl@4.0.2/dist/maplibre-gl.js" integrity="sha256-qmQe97oAYERiVjChfXOO7hB6XvtPv+LURdheDkwjygk=" crossorigin="anonymous"></script>
   <script src="https://baremaps.apache.org/assets/maplibre/maplibre-gl-inspect.js" integrity="sha256-NYdRoIbqeAWkTHjpa/BukMLXcsiqFoDuJCYzzaRei30=" crossorigin="anonymous"></script>
diff --git a/basemap/index.html b/basemap/index.html
index f903e4c5e..940c72f6a 100644
--- a/basemap/index.html
+++ b/basemap/index.html
@@ -15,7 +15,7 @@
 See the License for the specific language governing permissions and
 limitations under the License.
 -->
-<html>
+<html lang="en">
 <head>
   <script src='https://unpkg.com/maplibre-gl@4.0.2/dist/maplibre-gl.js'></script>
   <script src='https://baremaps.apache.org/assets/maplibre/maplibre-gl-inspect.js'></script>
diff --git a/examples/openstreetmap/index.html b/examples/openstreetmap/index.html
index f903e4c5e..940c72f6a 100644
--- a/examples/openstreetmap/index.html
+++ b/examples/openstreetmap/index.html
@@ -15,7 +15,7 @@
 See the License for the specific language governing permissions and
 limitations under the License.
 -->
-<html>
+<html lang="en">
 <head>
   <script src='https://unpkg.com/maplibre-gl@4.0.2/dist/maplibre-gl.js'></script>
   <script src='https://baremaps.apache.org/assets/maplibre/maplibre-gl-inspect.js'></script>
