diff --git a/NEWS b/NEWS
index 11b3936a..88793641 100644
--- a/NEWS
+++ b/NEWS
@@ -11,6 +11,7 @@ NEWS ( CHANGELOG and HISTORY )                                     HTMLPurifier
 
 2.1.4, unknown release date
 ! DefinitionCacheFactory now can register new implementations
+! CSS properties are now case-insensitive
 - Colors missing # but in hex form will be corrected
 - CSS Number algorithm improved
 
diff --git a/library/HTMLPurifier/AttrDef/CSS.php b/library/HTMLPurifier/AttrDef/CSS.php
index d0f49bc4..71523be1 100644
--- a/library/HTMLPurifier/AttrDef/CSS.php
+++ b/library/HTMLPurifier/AttrDef/CSS.php
@@ -38,7 +38,20 @@ class HTMLPurifier_AttrDef_CSS extends HTMLPurifier_AttrDef
             list($property, $value) = explode(':', $declaration, 2);
             $property = trim($property);
             $value    = trim($value);
-            if (!isset($definition->info[$property])) continue;
+            $ok = false;
+            do {
+                if (isset($definition->info[$property])) {
+                    $ok = true;
+                    break;
+                }
+                if (ctype_lower($property)) break;
+                $property = strtolower($property);
+                if (isset($definition->info[$property])) {
+                    $ok = true;
+                    break;
+                }
+            } while(0);
+            if (!$ok) continue;
             // inefficient call, since the validator will do this again
             if (strtolower(trim($value)) !== 'inherit') {
                 // inherit works for everything (but only on the base property)
diff --git a/tests/HTMLPurifier/AttrDef/CSSTest.php b/tests/HTMLPurifier/AttrDef/CSSTest.php
index 994fad12..59d86e2e 100644
--- a/tests/HTMLPurifier/AttrDef/CSSTest.php
+++ b/tests/HTMLPurifier/AttrDef/CSSTest.php
@@ -107,6 +107,9 @@ class HTMLPurifier_AttrDef_CSSTest extends HTMLPurifier_AttrDefHarness
         $this->assertDef(' font-weight : bold; color : #ff0000',
                          'font-weight:bold;color:#ff0000;');
         
+        // case-insensitivity
+        $this->assertDef('FLOAT:LEFT;', 'float:left;');
+        
     }
     
 }