diff --git a/CHANGELOG b/CHANGELOG
index 6f7e715ea..937db48ef 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,5 +1,8 @@
 #Nmap Changelog ($Id$); -*-text-*-
 
+o [NSE][GH#1999][GH#2005] IKE library was not properly populating the protocol
+  number in aggressive mode requests. [luc-x41]
+
 o [GH#1963] Added service fingerprinting for MySQL 8.x, Microsoft SQL
   Server 2019, MariaDB, and Crate.io CrateDB. Updated PostreSQL coverage and
   added specific detection of recent versions running in Docker. [Tom Sellers]
diff --git a/nselib/ike.lua b/nselib/ike.lua
index 18d16e4c9..d3278cb1e 100644
--- a/nselib/ike.lua
+++ b/nselib/ike.lua
@@ -405,7 +405,7 @@ local function generate_aggressive(port, protocol, id, diffie)
       0x00, -- Next Payload (None)
       #id + 4 + 4, -- Payload length
       0x03, -- ID Type (USER_FQDN)
-      PROTOCOL_IDS(protocol), -- Protocol ID (UDP)
+      PROTOCOL_IDS[protocol], -- Protocol ID (UDP)
       port) -- Port (500)
     .. id
     )