diff --git a/source/styx2000/protomsg/decoder.d b/source/styx2000/protomsg/decoder.d
index c507f2a..9340990 100644
--- a/source/styx2000/protomsg/decoder.d
+++ b/source/styx2000/protomsg/decoder.d
@@ -29,7 +29,7 @@ private {
 		E listOfTypes;
 		StyxObject[] msg;
 		
-		ulong vlsPosition = 0;
+		size_t vlsPosition = 0;
 	
 		foreach (e; listOfTypes)
 		{
diff --git a/source/styx2000/protomsg/encoder.d b/source/styx2000/protomsg/encoder.d
index e2f1c50..5c5ee02 100644
--- a/source/styx2000/protomsg/encoder.d
+++ b/source/styx2000/protomsg/encoder.d
@@ -122,7 +122,7 @@ auto encode(StyxObject[] msg)
 				throw new Exception(`Bad message content: wrong Styx type in message`);
 			}
 			
-			uint length = 0;
+			size_t length = 0;
 			
 			foreach (f; msg[1..$])
 			{