diff --git a/src/inet/networklayer/contract/NetworkHeaderBase.msg b/src/inet/networklayer/contract/NetworkHeaderBase.msg
index 2c9d4930610..69055d236cc 100644
--- a/src/inet/networklayer/contract/NetworkHeaderBase.msg
+++ b/src/inet/networklayer/contract/NetworkHeaderBase.msg
@@ -52,8 +52,8 @@ class NetworkHeaderBase extends FieldsChunk
 {
     @existingClass;
 
-    L3Address sourceAddress @byValue @toValue(.str()) @fromValue(Ipv4Address($));
-    L3Address destinationAddress @byValue @toValue(.str()) @fromValue(Ipv4Address($));
+    L3Address sourceAddress @byValue @toValue(.str()) @fromValue(L3Address($));
+    L3Address destinationAddress @byValue @toValue(.str()) @fromValue(L3Address($));
     const Protocol *protocol;
 };