diff --git a/lib/functions/filedir/function.safe_exec.php b/lib/functions/filedir/function.safe_exec.php
index 28b9c6c1..e72fdb00 100644
--- a/lib/functions/filedir/function.safe_exec.php
+++ b/lib/functions/filedir/function.safe_exec.php
@@ -82,7 +82,7 @@ function safe_exec($exec_string, &$return_value = false)
 	$ok = false;
 	foreach($allowed_commands as $allowed_command)
 	{
-		if(strpos($exec_string, $allowed_command) == 0
+		if(strpos($exec_string, $allowed_command) === 0
 		   && (strlen($exec_string) === ($allowed_command_pos = strlen($allowed_command)) || substr($exec_string, $allowed_command_pos, 1) === ' '))
 		{
 			$ok = true;