diff --git a/framework/logging/CLogRoute.php b/framework/logging/CLogRoute.php
index 5835354537..4e7cad0896 100644
--- a/framework/logging/CLogRoute.php
+++ b/framework/logging/CLogRoute.php
@@ -40,6 +40,7 @@ abstract class CLogRoute extends CComponent
 	public $levels='';
 	/**
 	 * @var string list of categories separated by comma or space. Defaults to empty, meaning all categories.
+	 * Allows negating categories, use ! before a category name to not include it.
 	 */
 	public $categories='';
 	/**
diff --git a/framework/logging/CLogger.php b/framework/logging/CLogger.php
index 84e37645d7..1233a35d15 100644
--- a/framework/logging/CLogger.php
+++ b/framework/logging/CLogger.php
@@ -149,13 +149,20 @@ public function getLogs($levels='',$categories='')
 	 */
 	private function filterByCategory($value)
 	{
+		$cat=strtolower($value[2]);
+		$negateOnly=true;
 		foreach($this->_categories as $category)
 		{
-			$cat=strtolower($value[2]);
+			if (substr($category, 0,1) === '!')
+				$category = substr($category,1);
+			else
+				$negateOnly = false;
+			
 			if($cat===$category || (($c=rtrim($category,'.*'))!==$category && strpos($cat,$c)===0))
-				return true;
+				return !$negateOnly;
+			
 		}
-		return false;
+		return $negateOnly;
 	}
 
 	/**