diff --git a/library/PCUIF_Types.ttcn b/library/PCUIF_Types.ttcn
index 27d9b92..f13a764 100644
--- a/library/PCUIF_Types.ttcn
+++ b/library/PCUIF_Types.ttcn
@@ -70,7 +70,7 @@
 	PCU_OML_ALERT			(1)
 } with { variant "FIELDLENGTH(8)" };
 
-type charstring PCUIF_Text length(128) with { variant "FIELDLENGTH(128)" };
+type charstring PCUIF_Text length(128) with { variant "FIELDLENGTH(null_terminated)" };
 
 type record PCUIF_txt_ind {
 	PCUIF_TextType	txt_type,