diff --git a/application/themehandler.class.inc.php b/application/themehandler.class.inc.php
index 1945c21b2..02bcf241d 100644
--- a/application/themehandler.class.inc.php
+++ b/application/themehandler.class.inc.php
@@ -342,7 +342,7 @@ CSS;
 			}
 		}
 
-		$aMap = ThemeHandler::ResolveUncompleteUrlsFromScss($aMap, $aThemeParametersVariables, $aStylesheetFile);
+		$aMap = static::ResolveUncompleteUrlsFromScss($aMap, $aThemeParametersVariables, $aStylesheetFile);
 		$aImages = array();
 		foreach ($aMap ['aCompleteUrls'] as $sUrl)
 		{