diff --git a/docs/markup.md b/docs/markup.md
index 50bb89f..d61509c 100644
--- a/docs/markup.md
+++ b/docs/markup.md
@@ -214,6 +214,7 @@ setAttribute(string $name, ?string $value): self
 $markup->setAttribute('id', 'main-content');
 $markup->setAttribute('data-user-id', '123');
 $markup->setAttribute('role', 'navigation');
+$markup->setAttribute('required', '');
 
 // Remove an attribute (null value)
 $markup->setAttribute('disabled', null);
@@ -1220,4 +1221,3 @@ $list = new Markup(
 - [MarkupQueryBuilder](markup-query-builder.html) - Fluent query builder
 - [MarkupCollection](markup-collection.html) - Collection methods
 - [Getting Started](getting-started.html) - Introduction and first steps
-
diff --git a/src/Markup.php b/src/Markup.php
index 809e380..840e4f4 100644
--- a/src/Markup.php
+++ b/src/Markup.php
@@ -664,7 +664,7 @@ public function classes( ?array $classes = null ) {
 	 * Sets or removes an HTML attribute on the wrapper element.
 	 *
 	 * If value is provided, sets the attribute. If value is null, removes the attribute.
-	 * For boolean attributes (e.g., disabled, readonly), pass the attribute name as the value.
+	 * For boolean attributes (e.g., disabled, readonly), pass an empty string as the value.
 	 *
 	 * @since 1.0.0
 	 *
@@ -1928,7 +1928,11 @@ private function wrapperOpenerTag(): string {
 		if ( ! empty( $this->wrapperAttributes ) ) {
 			$attributes = [];
 			foreach ( $this->wrapperAttributes as $attribute => $value ) {
-				$attributes[] = $attribute . '="' . $value . '"';
+				if ( '' === $value ) {
+					$attributes[] = $attribute;
+				} else {
+					$attributes[] = $attribute . '="' . htmlspecialchars( (string) $value, ENT_QUOTES | ENT_SUBSTITUTE, 'UTF-8' ) . '"';
+				}
 			}
 			$attributesStr = ' ' . implode( ' ', $attributes );
 		} else {
@@ -2092,4 +2096,3 @@ private function renderSlot( MarkupSlot $slot ): string {
 	}
 
 }
-