diff --git a/puppet/files/puppet-check b/puppet/files/puppet-check
index 3b5258f..4281eb8 100755
--- a/puppet/files/puppet-check
+++ b/puppet/files/puppet-check
@@ -26,7 +26,7 @@ begin
     Process.kill(0, pid)
 
     # check memory usage and restart if over 256M
-    rss = `ps -o rss= -p '#{pid}'`.to_i / 1024
+    rss = `ps -o rss -p '#{pid}'`.to_a.last.to_i / 1024
     if rss > 256
         printf("puppetd memory usage too high (%d MB), on host '%s' sending HUP\n",
                rss, Socket.gethostname)