diff --git a/rtl/go32v2/ports.pp b/rtl/go32v2/ports.pp
index 04de974cc7..e59880ac52 100644
--- a/rtl/go32v2/ports.pp
+++ b/rtl/go32v2/ports.pp
@@ -16,10 +16,6 @@
 
 unit ports;
 
-{$ifdef VER3_0}
-{$Calling StdCall}
-{$endif VER3_0}
-
 {$inline ON}
 
 interface
diff --git a/rtl/i386/ports.inc b/rtl/i386/ports.inc
index 6f286026a8..0cc28a33d0 100644
--- a/rtl/i386/ports.inc
+++ b/rtl/i386/ports.inc
@@ -19,7 +19,7 @@
 { to give easy port access like tp with port[] }
 
 {$ifdef VER3_0}
-procedure tport.writeport(p : word;data : byte);assembler;
+procedure tport.writeport(p : word;data : byte);assembler;stdcall;
 asm
         movw    p,%dx
         movb    data,%al
@@ -27,14 +27,14 @@ asm
 end;
 
 
-function tport.readport(p : word) : byte;assembler;
+function tport.readport(p : word) : byte;assembler;stdcall;
 asm
         movw    p,%dx
         inb     %dx,%al
 end;
 
 
-procedure tportw.writeport(p : word;data : word);assembler;
+procedure tportw.writeport(p : word;data : word);assembler;stdcall;
 asm
         movw    p,%dx
         movw    data,%ax
@@ -42,14 +42,14 @@ asm
 end;
 
 
-function tportw.readport(p : word) : word;assembler;
+function tportw.readport(p : word) : word;assembler;stdcall;
 asm
         movw    p,%dx
         inw     %dx,%ax
 end;
 
 
-procedure tportl.writeport(p : word;data : longint);assembler;
+procedure tportl.writeport(p : word;data : longint);assembler;stdcall;
 asm
         movw    p,%dx
         movl    data,%eax
@@ -57,7 +57,7 @@ asm
 end;
 
 
-function tportl.readport(p : word) : longint;assembler;
+function tportl.readport(p : word) : longint;assembler;stdcall;
 asm
         movw    p,%dx
         inl     %dx,%eax
diff --git a/rtl/i386/portsh.inc b/rtl/i386/portsh.inc
index 25903fcf4b..147400b418 100644
--- a/rtl/i386/portsh.inc
+++ b/rtl/i386/portsh.inc
@@ -17,20 +17,20 @@
 type
 {$ifdef VER3_0}
    tport = object
-      procedure writeport(p : word;data : byte);
-      function  readport(p : word) : byte;
+      procedure writeport(p : word;data : byte);stdcall;
+      function  readport(p : word) : byte;stdcall;
       property pp[w : word] : byte read readport write writeport;default;
    end;
 
    tportw = object
-      procedure writeport(p : word;data : word);
-      function  readport(p : word) : word;
+      procedure writeport(p : word;data : word);stdcall;
+      function  readport(p : word) : word;stdcall;
       property pp[w : word] : word read readport write writeport;default;
    end;
 
    tportl = object
-      procedure writeport(p : word;data : longint);
-      function  readport(p : word) : longint;
+      procedure writeport(p : word;data : longint);stdcall;
+      function  readport(p : word) : longint;stdcall;
       property pp[w : word] : longint read readport write writeport;default;
    end;
 {$else VER3_0}