diff --git a/scripts/clamav-exec.nse b/scripts/clamav-exec.nse
index d426428ea..258ce06e9 100644
--- a/scripts/clamav-exec.nse
+++ b/scripts/clamav-exec.nse
@@ -82,7 +82,7 @@ author = "Paulino Calderon <calderon()websec.mx>"
 license = "Same as Nmap--See https://nmap.org/book/man-legal.html"
 categories = {"exploit", "vuln"}
 
-portrule = shortport.port_or_service{3310, "clam"}
+portrule = shortport.port_or_service(3310, "clam")
 
 local function shutdown(host, port)
   local status, data = comm.exchange(host, port, "SHUTDOWN")