diff --git a/lib/stdlib.inc b/lib/stdlib.inc
index ee107b3..62eb8fc 100644
--- a/lib/stdlib.inc
+++ b/lib/stdlib.inc
@@ -150,8 +150,8 @@ procedure strmovedown(var s:string;index,length,delta:integer); external;
 procedure RuntimeError(var s:string); external;
 
 (* from stdlib *)
-function copy(s:string;index,count:integer):string; external;
-procedure insert(ins: string; var dest: string; position:integer); external;
+function copy(s:string[256];index,count:integer):string[256]; external;
+procedure insert(ins:string[256]; var dest:string[256]; position:integer); external;
 procedure delete(var s:string; from:integer; count:integer); external;
 function pos(substr:string;var s:string):integer; external;
 function pwroften(exp:integer):real; external;
diff --git a/lib/stdlib.pas b/lib/stdlib.pas
index cbd0840..945ece9 100644
--- a/lib/stdlib.pas
+++ b/lib/stdlib.pas
@@ -402,7 +402,7 @@ begin
 	GetCurTimestamp := GetTimestamp(now);
 end;
 
-function copy(s:string;index,count:integer):string;
+function copy(s:string[256];index,count:integer):string[256];
 var len:integer;
 begin
 	copy := '';
@@ -416,7 +416,7 @@ begin
 	end;
 end;
 
-procedure insert(ins: string; var dest: string; position:integer);
+procedure insert(ins:string[256]; var dest:string[256]; position:integer);
 var i,count,from,to_:integer;
 begin
 	if position < 1 then position := 1;