diff --git a/src/IP.cc b/src/IP.cc
index 647461d526..28109b185a 100644
--- a/src/IP.cc
+++ b/src/IP.cc
@@ -298,6 +298,9 @@ IntrusivePtr<RecordVal> IPv6_Hdr::ToVal(IntrusivePtr<VectorVal> chain) const
 	return rv;
 	}
 
+IntrusivePtr<RecordVal> IPv6_Hdr::ToVal() const
+	{ return ToVal(nullptr); }
+
 RecordVal* IPv6_Hdr::BuildRecordVal(VectorVal* chain) const
 	{
 	return ToVal({AdoptRef{}, chain}).release();
diff --git a/src/IP.h b/src/IP.h
index 2959a6dd1a..3bb1a6c897 100644
--- a/src/IP.h
+++ b/src/IP.h
@@ -136,7 +136,8 @@ public:
 	/**
 	 * Returns the script-layer record representation of the header.
 	 */
-	IntrusivePtr<RecordVal> ToVal(IntrusivePtr<VectorVal> chain = nullptr) const;
+	IntrusivePtr<RecordVal> ToVal(IntrusivePtr<VectorVal> chain) const;
+	IntrusivePtr<RecordVal> ToVal() const;
 
 	[[deprecated("Remove in v4.1.  Use ToVal() instead.")]]
 	RecordVal* BuildRecordVal(VectorVal* chain = nullptr) const;