diff --git a/CHANGELOG b/CHANGELOG
index d9690d1..da9a811 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,5 +1,7 @@
 *SVN*
 
+* Ensure Element#hasClassName always returns a boolean. Closes #10075. [ronnylovtangen, Tobie Langel]
+
 * Ensure selectors of the form "[href]" (attribute token with no preceding tag name) work properly. Closes #8870. [chao, kangax, Andrew Dupont]
 
 * Performance optimizations for Element#descendantOf. Costliness should no longer be dependent on the difference in depth between the parent and the child. [Andrew Dupont]
diff --git a/src/dom.js b/src/dom.js
index 086cf71..f2367f4 100644
--- a/src/dom.js
+++ b/src/dom.js
@@ -316,7 +316,7 @@ Element.Methods = {
     if (!(element = $(element))) return;
     var elementClassName = element.className;
     return (elementClassName.length > 0 && (elementClassName == className || 
-      elementClassName.match(new RegExp("(^|\\s)" + className + "(\\s|$)"))));
+      new RegExp("(^|\\s)" + className + "(\\s|$)").test(elementClassName)));
   },
 
   addClassName: function(element, className) {
diff --git a/test/unit/dom.html b/test/unit/dom.html
index 1ed5565..59d7897 100644
--- a/test/unit/dom.html
+++ b/test/unit/dom.html
@@ -1403,12 +1403,12 @@
     }},
     
     testHasClassName: function() {with(this) {
-      assert(!$('class_names').hasClassName('does_not_exist'));
-      assert($('class_names').down().hasClassName('A'));
-      assert(!$('class_names').down().hasClassName('does_not_exist'));
-      assert($('class_names_ul').hasClassName('A'));
-      assert($('class_names_ul').hasClassName('B'));
-      assert(!$('class_names_ul').hasClassName('does_not_exist'));
+      assertIdentical(false, $('class_names').hasClassName('does_not_exist'));
+      assertIdentical(true, $('class_names').down().hasClassName('A'));
+      assertIdentical(false, $('class_names').down().hasClassName('does_not_exist'));
+      assertIdentical(true, $('class_names_ul').hasClassName('A'));
+      assertIdentical(true, $('class_names_ul').hasClassName('B'));
+      assertIdentical(false, $('class_names_ul').hasClassName('does_not_exist'));
     }},
     
     testAddClassName: function() {with(this) {