diff --git a/library/IPA_CodecPort_CtrlFunct.ttcn b/library/IPA_CodecPort_CtrlFunct.ttcn
index c0e7de6..88ab01f 100644
--- a/library/IPA_CodecPort_CtrlFunct.ttcn
+++ b/library/IPA_CodecPort_CtrlFunct.ttcn
@@ -40,5 +40,13 @@
     out UserData userData
   ) return Result;
 
+  external function f_IPL4_setGetMsgLen(
+    inout IPA_CODEC_PT portRef,
+    in ConnectionId id,
+    inout f_IPL4_getMsgLen f,
+    in ro_integer msgLenArgs
+  );
+
+
 }