diff --git a/pom.xml b/pom.xml
index 1f55c4cb..cf6b50df 100644
--- a/pom.xml
+++ b/pom.xml
@@ -1,4 +1,4 @@
-<?xml version="1.0"?>
+<?xml version="1.0" encoding="UTF-8"?>
 <!--
  * SPDX-FileCopyrightText: Copyright (c) 2012-2025, Yegor Bugayenko
  * SPDX-License-Identifier: MIT
diff --git a/s3auth-hosts/pom.xml b/s3auth-hosts/pom.xml
index 692c3356..9b9ff396 100644
--- a/s3auth-hosts/pom.xml
+++ b/s3auth-hosts/pom.xml
@@ -1,4 +1,4 @@
-<?xml version="1.0"?>
+<?xml version="1.0" encoding="UTF-8"?>
 <!--
  * SPDX-FileCopyrightText: Copyright (c) 2012-2025, Yegor Bugayenko
  * SPDX-License-Identifier: MIT
diff --git a/s3auth-hosts/src/main/resources/com/s3auth/hosts/directory.xsl b/s3auth-hosts/src/main/resources/com/s3auth/hosts/directory.xsl
index 22299c10..de60a67a 100644
--- a/s3auth-hosts/src/main/resources/com/s3auth/hosts/directory.xsl
+++ b/s3auth-hosts/src/main/resources/com/s3auth/hosts/directory.xsl
@@ -1,4 +1,4 @@
-<?xml version="1.0"?>
+<?xml version="1.0" encoding="UTF-8"?>
 <!--
  * SPDX-FileCopyrightText: Copyright (c) 2012-2025, Yegor Bugayenko
  * SPDX-License-Identifier: MIT
diff --git a/s3auth-hosts/src/main/resources/com/s3auth/hosts/versions.xsl b/s3auth-hosts/src/main/resources/com/s3auth/hosts/versions.xsl
index de37beb3..168b94dc 100644
--- a/s3auth-hosts/src/main/resources/com/s3auth/hosts/versions.xsl
+++ b/s3auth-hosts/src/main/resources/com/s3auth/hosts/versions.xsl
@@ -1,4 +1,4 @@
-<?xml version="1.0"?>
+<?xml version="1.0" encoding="UTF-8"?>
 <!--
  * SPDX-FileCopyrightText: Copyright (c) 2012-2025, Yegor Bugayenko
  * SPDX-License-Identifier: MIT
diff --git a/s3auth-hosts/src/site/site.xml b/s3auth-hosts/src/site/site.xml
index e014a795..4931edc3 100644
--- a/s3auth-hosts/src/site/site.xml
+++ b/s3auth-hosts/src/site/site.xml
@@ -1,4 +1,4 @@
-<?xml version="1.0"?>
+<?xml version="1.0" encoding="UTF-8"?>
 <!--
  * SPDX-FileCopyrightText: Copyright (c) 2012-2025, Yegor Bugayenko
  * SPDX-License-Identifier: MIT
diff --git a/s3auth-relay/pom.xml b/s3auth-relay/pom.xml
index ad48eb9c..00c910c2 100644
--- a/s3auth-relay/pom.xml
+++ b/s3auth-relay/pom.xml
@@ -1,4 +1,4 @@
-<?xml version="1.0"?>
+<?xml version="1.0" encoding="UTF-8"?>
 <!--
  * SPDX-FileCopyrightText: Copyright (c) 2012-2025, Yegor Bugayenko
  * SPDX-License-Identifier: MIT
diff --git a/s3auth-relay/src/it/non-daemon/pom.xml b/s3auth-relay/src/it/non-daemon/pom.xml
index f80fcae5..04a2fdbb 100644
--- a/s3auth-relay/src/it/non-daemon/pom.xml
+++ b/s3auth-relay/src/it/non-daemon/pom.xml
@@ -1,4 +1,4 @@
-<?xml version="1.0"?>
+<?xml version="1.0" encoding="UTF-8"?>
 <!--
  * SPDX-FileCopyrightText: Copyright (c) 2012-2025, Yegor Bugayenko
  * SPDX-License-Identifier: MIT
diff --git a/s3auth-relay/src/it/settings.xml b/s3auth-relay/src/it/settings.xml
index 7c2ef4f4..83eb8b6b 100644
--- a/s3auth-relay/src/it/settings.xml
+++ b/s3auth-relay/src/it/settings.xml
@@ -1,4 +1,4 @@
-<?xml version="1.0"?>
+<?xml version="1.0" encoding="UTF-8"?>
 <!--
  * SPDX-FileCopyrightText: Copyright (c) 2012-2025, Yegor Bugayenko
  * SPDX-License-Identifier: MIT
diff --git a/s3auth-relay/src/main/production/pom.xml b/s3auth-relay/src/main/production/pom.xml
index 094f5412..d303fb60 100644
--- a/s3auth-relay/src/main/production/pom.xml
+++ b/s3auth-relay/src/main/production/pom.xml
@@ -1,4 +1,4 @@
-<?xml version="1.0"?>
+<?xml version="1.0" encoding="UTF-8"?>
 <!--
  * SPDX-FileCopyrightText: Copyright (c) 2012-2025, Yegor Bugayenko
  * SPDX-License-Identifier: MIT
diff --git a/s3auth-relay/src/site/site.xml b/s3auth-relay/src/site/site.xml
index a54a0925..452c6a51 100644
--- a/s3auth-relay/src/site/site.xml
+++ b/s3auth-relay/src/site/site.xml
@@ -1,4 +1,4 @@
-<?xml version="1.0"?>
+<?xml version="1.0" encoding="UTF-8"?>
 <!--
  * SPDX-FileCopyrightText: Copyright (c) 2012-2025, Yegor Bugayenko
  * SPDX-License-Identifier: MIT
diff --git a/s3auth-rest/pom.xml b/s3auth-rest/pom.xml
index 8a2a314a..19bee892 100644
--- a/s3auth-rest/pom.xml
+++ b/s3auth-rest/pom.xml
@@ -1,4 +1,4 @@
-<?xml version="1.0"?>
+<?xml version="1.0" encoding="UTF-8"?>
 <!--
  * SPDX-FileCopyrightText: Copyright (c) 2012-2025, Yegor Bugayenko
  * SPDX-License-Identifier: MIT
diff --git a/s3auth-rest/src/main/xsl/404.xsl b/s3auth-rest/src/main/xsl/404.xsl
index 5fd5384b..5a9e3b86 100644
--- a/s3auth-rest/src/main/xsl/404.xsl
+++ b/s3auth-rest/src/main/xsl/404.xsl
@@ -1,4 +1,4 @@
-<?xml version="1.0"?>
+<?xml version="1.0" encoding="UTF-8"?>
 <!--
  * SPDX-FileCopyrightText: Copyright (c) 2012-2025, Yegor Bugayenko
  * SPDX-License-Identifier: MIT
diff --git a/s3auth-rest/src/main/xsl/index.xsl b/s3auth-rest/src/main/xsl/index.xsl
index b1df3ca1..b7652d4b 100644
--- a/s3auth-rest/src/main/xsl/index.xsl
+++ b/s3auth-rest/src/main/xsl/index.xsl
@@ -1,4 +1,4 @@
-<?xml version="1.0"?>
+<?xml version="1.0" encoding="UTF-8"?>
 <!--
  * SPDX-FileCopyrightText: Copyright (c) 2012-2025, Yegor Bugayenko
  * SPDX-License-Identifier: MIT
diff --git a/s3auth-rest/src/main/xsl/layout.xsl b/s3auth-rest/src/main/xsl/layout.xsl
index 3b2306e7..ef616601 100644
--- a/s3auth-rest/src/main/xsl/layout.xsl
+++ b/s3auth-rest/src/main/xsl/layout.xsl
@@ -1,4 +1,4 @@
-<?xml version="1.0"?>
+<?xml version="1.0" encoding="UTF-8"?>
 <!--
  * SPDX-FileCopyrightText: Copyright (c) 2012-2025, Yegor Bugayenko
  * SPDX-License-Identifier: MIT
diff --git a/s3auth-rest/src/main/xsl/login.xsl b/s3auth-rest/src/main/xsl/login.xsl
index 937641e9..0024baf2 100644
--- a/s3auth-rest/src/main/xsl/login.xsl
+++ b/s3auth-rest/src/main/xsl/login.xsl
@@ -1,4 +1,4 @@
-<?xml version="1.0"?>
+<?xml version="1.0" encoding="UTF-8"?>
 <!--
  * SPDX-FileCopyrightText: Copyright (c) 2012-2025, Yegor Bugayenko
  * SPDX-License-Identifier: MIT
diff --git a/s3auth-rest/src/site/site.xml b/s3auth-rest/src/site/site.xml
index 3ce914f5..5c6b6cc3 100644
--- a/s3auth-rest/src/site/site.xml
+++ b/s3auth-rest/src/site/site.xml
@@ -1,4 +1,4 @@
-<?xml version="1.0"?>
+<?xml version="1.0" encoding="UTF-8"?>
 <!--
  * SPDX-FileCopyrightText: Copyright (c) 2012-2025, Yegor Bugayenko
  * SPDX-License-Identifier: MIT
diff --git a/s3auth-rest/src/test/resources/directory.xml b/s3auth-rest/src/test/resources/directory.xml
index 1f453eb3..72844294 100644
--- a/s3auth-rest/src/test/resources/directory.xml
+++ b/s3auth-rest/src/test/resources/directory.xml
@@ -1,4 +1,4 @@
-<?xml version="1.0"?>
+<?xml version="1.0" encoding="UTF-8"?>
 <!--
  * SPDX-FileCopyrightText: Copyright (c) 2012-2025, Yegor Bugayenko
  * SPDX-License-Identifier: MIT
diff --git a/src/site/site.xml b/src/site/site.xml
index 70038b9a..a629f512 100644
--- a/src/site/site.xml
+++ b/src/site/site.xml
@@ -1,4 +1,4 @@
-<?xml version="1.0"?>
+<?xml version="1.0" encoding="UTF-8"?>
 <!--
  * SPDX-FileCopyrightText: Copyright (c) 2012-2025, Yegor Bugayenko
  * SPDX-License-Identifier: MIT