diff --git a/CASA/micasad/verbs/ObjectSerialization.cs b/CASA/micasad/verbs/ObjectSerialization.cs
index 72a7b473..0b6f54c9 100644
--- a/CASA/micasad/verbs/ObjectSerialization.cs
+++ b/CASA/micasad/verbs/ObjectSerialization.cs
@@ -331,7 +331,7 @@ namespace sscs.verbs
 
 #if LINUX
 				// change file ownership to the user 
-				Mono.Unix.Native.Syscall.chown(sFilePath, userId.GetUID(), userId.GetUID());				
+				Mono.Unix.Native.Syscall.chown(sFilePath, (uint)userId.GetUID(), (uint)userId.GetUID());				
 #endif
 
 			}