diff --git a/src/Languages/Html/Patterns/HtmlCloseTagPattern.php b/src/Languages/Html/Patterns/HtmlCloseTagPattern.php
index c8ee301d..ec2fc122 100644
--- a/src/Languages/Html/Patterns/HtmlCloseTagPattern.php
+++ b/src/Languages/Html/Patterns/HtmlCloseTagPattern.php
@@ -14,7 +14,10 @@
 #[PatternTest(input: '</CamelCase>', output: 'CamelCase')]
 #[PatternTest(input: '</x-hello>', output: 'x-hello')]
 #[PatternTest(input: '</a>', output: 'a')]
+#[PatternTest(input: '</math-α>', output: 'math-α')]
+#[PatternTest(input: '</emotion-😍-emoji>', output: 'emotion-😍-emoji')]
 # The following are not HTML valid
+#[PatternTest(input: '</αtag>', output: null)]
 #[PatternTest(input: '</ns:tag>', output: null)]
 #[PatternTest(input: '</point.x>', output: null)]
 #[PatternTest(input: '</point_y>', output: null)]
@@ -27,7 +30,7 @@
 
     public function getPattern(): string
     {
-        return '<\/(?<match>[a-zA-Z][a-zA-Z0-9\-]*(?![:_\.\w]))';
+        return '<\/(?<match>[a-zA-Z][a-zA-Z0-9\-\x80-\xFF]*(?![:_\.\w\x80-\xFF]))';
     }
 
     public function getTokenType(): TokenTypeEnum
diff --git a/src/Languages/Html/Patterns/HtmlOpenTagPattern.php b/src/Languages/Html/Patterns/HtmlOpenTagPattern.php
index ee7c488d..bb5f9c25 100644
--- a/src/Languages/Html/Patterns/HtmlOpenTagPattern.php
+++ b/src/Languages/Html/Patterns/HtmlOpenTagPattern.php
@@ -14,7 +14,10 @@
 #[PatternTest(input: '<CamelCase>', output: 'CamelCase')]
 #[PatternTest(input: '<a-component>', output: 'a-component')]
 #[PatternTest(input: '<a href="">', output: 'a')]
+#[PatternTest(input: '<math-α>', output: 'math-α')]
+#[PatternTest(input: '<emotion-😍-emoji>', output: 'emotion-😍-emoji')]
 # The following are not HTML valid
+#[PatternTest(input: '<αtag>', output: null)]
 #[PatternTest(input: '<_private>', output: null)]
 #[PatternTest(input: '<ns:tag>', output: null)]
 #[PatternTest(input: '<point.x>', output: null)]
@@ -27,7 +30,7 @@
 
     public function getPattern(): string
     {
-        return '<(?<match>[a-zA-Z][a-zA-Z0-9\-]*(?![:_\.\w]))';
+        return '<(?<match>[a-zA-Z][a-zA-Z0-9\-\x80-\xFF]*(?![:_\.\w\x80-\xFF]))';
     }
 
     public function getTokenType(): TokenTypeEnum
diff --git a/src/Languages/Xml/Patterns/XmlCloseTagPattern.php b/src/Languages/Xml/Patterns/XmlCloseTagPattern.php
index f784f131..d6033c21 100644
--- a/src/Languages/Xml/Patterns/XmlCloseTagPattern.php
+++ b/src/Languages/Xml/Patterns/XmlCloseTagPattern.php
@@ -18,6 +18,9 @@
 #[PatternTest(input: '</point.x>', output: 'point.x')]
 #[PatternTest(input: '</point_y>', output: 'point_y')]
 #[PatternTest(input: '</_private>', output: '_private')]
+#[PatternTest(input: '</données>', output: 'données')]
+#[PatternTest(input: '</élément>', output: 'élément')]
+#[PatternTest(input: '</数据>', output: '数据')]
 # The following are not valid XML tags
 #[PatternTest(input: '</1tag>', output: null)]
 #[PatternTest(input: '</-tag>', output: null)]
@@ -27,7 +30,7 @@
 
     public function getPattern(): string
     {
-        return '<\/(?<match>[a-zA-Z_][\w\-\:\.]*)';
+        return '<\/(?<match>[a-zA-Z_\x80-\xFF][\w\-\:\.\x80-\xFF]*)';
     }
 
     public function getTokenType(): TokenTypeEnum
diff --git a/src/Languages/Xml/Patterns/XmlOpenTagPattern.php b/src/Languages/Xml/Patterns/XmlOpenTagPattern.php
index 0fb7fb8b..3c6b4c28 100644
--- a/src/Languages/Xml/Patterns/XmlOpenTagPattern.php
+++ b/src/Languages/Xml/Patterns/XmlOpenTagPattern.php
@@ -19,6 +19,9 @@
 #[PatternTest(input: '<point.x>', output: 'point.x')]
 #[PatternTest(input: '<point_y>', output: 'point_y')]
 #[PatternTest(input: '<_private>', output: '_private')]
+#[PatternTest(input: '<données>', output: 'données')]
+#[PatternTest(input: '<élément>', output: 'élément')]
+#[PatternTest(input: '<数据>', output: '数据')]
 # The following are not valid XML tags
 #[PatternTest(input: '<1tag>', output: null)]
 #[PatternTest(input: '<-tag>', output: null)]
@@ -28,7 +31,7 @@
 
     public function getPattern(): string
     {
-        return '<(?<match>[a-zA-Z_][\w\-\:\.]*)';
+        return '<(?<match>[a-zA-Z_\x80-\xFF][\w\-\:\.\x80-\xFF]*)';
     }
 
     public function getTokenType(): TokenTypeEnum
diff --git a/tests/Languages/Html/HtmlLanguageTest.php b/tests/Languages/Html/HtmlLanguageTest.php
index 3653fa12..719e50bf 100644
--- a/tests/Languages/Html/HtmlLanguageTest.php
+++ b/tests/Languages/Html/HtmlLanguageTest.php
@@ -48,6 +48,8 @@ public static function provide_highlight_cases(): iterable
     &lt;?php <span class="hl-property">foo</span>(); ?&gt;
 &lt;/<span class="hl-keyword">tag</span>&gt;
 TXT],
+            ['<math-α></math-α>', '&lt;<span class="hl-keyword">math-α</span>&gt;&lt;/<span class="hl-keyword">math-α</span>&gt;'],
+            ['<emotion-😍-emoji></emotion-😍-emoji>', '&lt;<span class="hl-keyword">emotion-😍-emoji</span>&gt;&lt;/<span class="hl-keyword">emotion-😍-emoji</span>&gt;'],
         ];
     }
 }
diff --git a/tests/Languages/Xml/XmlLanguageTest.php b/tests/Languages/Xml/XmlLanguageTest.php
index aa0ed1f4..f423ce23 100644
--- a/tests/Languages/Xml/XmlLanguageTest.php
+++ b/tests/Languages/Xml/XmlLanguageTest.php
@@ -40,6 +40,8 @@ public static function provide_highlight_cases(): iterable
 TXT],
             ["<ns:tag><tag></tag></ns:tag>", '&lt;<span class="hl-keyword">ns:tag</span>&gt;&lt;<span class="hl-keyword">tag</span>&gt;&lt;/<span class="hl-keyword">tag</span>&gt;&lt;/<span class="hl-keyword">ns:tag</span>&gt;'],
             ['<root xmlns:ns="...">', '&lt;<span class="hl-keyword">root</span> <span class="hl-property">xmlns:ns</span>=&quot;...&quot;&gt;'],
+            ['<données>1</données>', '&lt;<span class="hl-keyword">données</span>&gt;1&lt;/<span class="hl-keyword">données</span>&gt;'],
+            ['<élément></élément>', '&lt;<span class="hl-keyword">élément</span>&gt;&lt;/<span class="hl-keyword">élément</span>&gt;'],
         ];
     }
 }