diff --git a/rtl/i8086/stringss.inc b/rtl/i8086/stringss.inc
index 617cfd5b67..b993c2f764 100644
--- a/rtl/i8086/stringss.inc
+++ b/rtl/i8086/stringss.inc
@@ -41,7 +41,7 @@
 
 {$ifndef FPC_UNIT_HAS_STRPCOPY}
 {$define FPC_UNIT_HAS_STRPCOPY}
-function strpcopy(d : PAnsiChar;const s : string) : PAnsiChar;assembler;nostackframe;
+function strpcopy(d : PAnsiChar;const s : shortstring) : PAnsiChar;assembler;nostackframe;
 const
   { used for an offset fixup for accessing the proc parameters in asm routines
     that use nostackframe. We can't use the parameter name directly, because