diff --git a/static/man.php b/static/man.php
index fb206f6..d807aa5 100644
--- a/static/man.php
+++ b/static/man.php
@@ -21,7 +21,7 @@ $command = $_GET["command"];
 echo $command;
 $output=null;
 $retval=null;
-exec('man --html=cat ' . $command , $output, $retval);
+exec('man --html=cat '.escapeshellarg($command) , $output, $retval);
 echo "Returned with status $retval and output:\n"; 
 foreach ($output as $line): ?>
 <?=$line?>