diff --git a/phpgwapi/inc/class.egw_include_mgr.inc.php b/phpgwapi/inc/class.egw_include_mgr.inc.php
index 67bbc6eebb..520f2e59e8 100644
--- a/phpgwapi/inc/class.egw_include_mgr.inc.php
+++ b/phpgwapi/inc/class.egw_include_mgr.inc.php
@@ -297,7 +297,7 @@ class egw_include_mgr
 
 		if (self::$DEBUG_MODE) // DEBUG_MODE is currently ALWAYS true. Comment this code out if you don't want error messages.
 		{
-			error_log(__METHOD__."($package,$file,$app) $path NOT found".($this->debug_processing_file ? " while processing file '{$this->debug_processing_file}'." : "!"));
+			error_log(__METHOD__."($package,$file,$app) $path NOT found".($this->debug_processing_file ? " while processing file '{$this->debug_processing_file}'." : "!").' '.function_backtrace());
 		}
 
 		return false;