diff --git a/rtl/amiga/sysutils.pp b/rtl/amiga/sysutils.pp
index f3bcfff2fa..e98428dede 100644
--- a/rtl/amiga/sysutils.pp
+++ b/rtl/amiga/sysutils.pp
@@ -157,7 +157,7 @@ begin
   FileSeek:=dosSeek(Handle, FOffset, seekMode);
 end;
 
-function FileSeek(Handle: LongInt; FOffset, Origin: Int64): Int64;
+function FileSeek(Handle: LongInt; FOffset: Int64; Origin: Longint): Int64;
 begin
   {$WARNING Need to add 64bit call }
   FileSeek:=FileSeek(Handle,LongInt(FOffset),LongInt(Origin));
diff --git a/rtl/beos/sysutils.pp b/rtl/beos/sysutils.pp
index db42f34213..3b9764021c 100644
--- a/rtl/beos/sysutils.pp
+++ b/rtl/beos/sysutils.pp
@@ -71,7 +71,7 @@ Function FileSeek (Handle,FOffset,Origin : longint) : longint;
 begin
 end;
 
-Function FileSeek (Handle:longint;FOffset,Origin : int64) : int64;
+Function FileSeek (Handle:longint;FOffset: Int64; Origin: Longint) : int64;
 begin
 end;
 
diff --git a/rtl/emx/sysutils.pp b/rtl/emx/sysutils.pp
index 9e9677b6f1..f3aca4904c 100644
--- a/rtl/emx/sysutils.pp
+++ b/rtl/emx/sysutils.pp
@@ -494,7 +494,7 @@ asm
  pop ebx
 end {['eax', 'ebx', 'edx']};
 
-function FileSeek (Handle: longint; FOffset, Origin: Int64): Int64;
+function FileSeek (Handle: longint; FOffset: Int64; Origin: longint): Int64;
 begin
   {$warning need to add 64bit call }
   Result:=FileSeek(Handle,Longint(Foffset),Longint(Origin));
diff --git a/rtl/gba/sysutils.pp b/rtl/gba/sysutils.pp
index 79feeffa22..544344d5b4 100644
--- a/rtl/gba/sysutils.pp
+++ b/rtl/gba/sysutils.pp
@@ -91,7 +91,7 @@ begin
   result := -1;
 end;
 
-function FileSeek(Handle: LongInt; FOffset, Origin: Int64): Int64;
+function FileSeek(Handle: LongInt; FOffset: Int64; Origin: Longint): Int64;
 begin
   result := -1;
 end;
diff --git a/rtl/go32v2/sysutils.pp b/rtl/go32v2/sysutils.pp
index 6a6665be27..d55c9791cb 100644
--- a/rtl/go32v2/sysutils.pp
+++ b/rtl/go32v2/sysutils.pp
@@ -221,7 +221,7 @@ begin
 end;
 
 
-Function FileSeek (Handle : Longint; FOffset,Origin : Int64) : Int64;
+Function FileSeek (Handle : Longint; FOffset: Int64; Origin: Integer) : Int64;
 begin
   {$warning need to add 64bit call }
   FileSeek:=FileSeek(Handle,Longint(FOffset),Longint(Origin));
diff --git a/rtl/macos/sysutils.pp b/rtl/macos/sysutils.pp
index d140c81c81..0fe47cf77d 100644
--- a/rtl/macos/sysutils.pp
+++ b/rtl/macos/sysutils.pp
@@ -136,7 +136,7 @@ begin
 end;
 
 
-Function FileSeek (Handle : Longint; FOffset,Origin : Int64) : Int64;
+Function FileSeek (Handle : Longint; FOffset: Int64; Origin : Longint) : Int64;
 
 begin
   (* TODO fix
diff --git a/rtl/morphos/sysutils.pp b/rtl/morphos/sysutils.pp
index d0240306e9..3850499850 100644
--- a/rtl/morphos/sysutils.pp
+++ b/rtl/morphos/sysutils.pp
@@ -157,7 +157,7 @@ begin
   FileSeek:=dosSeek(Handle, FOffset, seekMode);
 end;
 
-function FileSeek(Handle: LongInt; FOffset, Origin: Int64): Int64;
+function FileSeek(Handle: LongInt; FOffset: Int64; Origin: Longint): Int64;
 begin
   {$WARNING Need to add 64bit call }
   FileSeek:=FileSeek(Handle,LongInt(FOffset),LongInt(Origin));
diff --git a/rtl/netware/sysutils.pp b/rtl/netware/sysutils.pp
index 67c411b85f..313fe547b9 100644
--- a/rtl/netware/sysutils.pp
+++ b/rtl/netware/sysutils.pp
@@ -132,7 +132,7 @@ begin
 end;
 
 
-Function FileSeek (Handle : THandle; FOffset,Origin : Int64) : Int64;
+Function FileSeek (Handle : THandle; FOffset: Int64; Origin: Longint) : Int64;
 begin
   {$warning need to add 64bit FileSeek }
   FileSeek:=FileSeek(Handle,Longint(FOffset),Longint(Origin));
diff --git a/rtl/netwlibc/sysutils.pp b/rtl/netwlibc/sysutils.pp
index a99da16ade..4c6342fc82 100644
--- a/rtl/netwlibc/sysutils.pp
+++ b/rtl/netwlibc/sysutils.pp
@@ -131,7 +131,7 @@ begin
 end;
 
 
-Function FileSeek (Handle : THandle; FOffset,Origin : Int64) : Int64;
+Function FileSeek (Handle : THandle; FOffset: Int64; Origin: Longint) : Int64;
 begin
   FileSeek:=libc.fplseek64 (Handle,FOffset,Origin);
 end;
diff --git a/rtl/os2/sysutils.pp b/rtl/os2/sysutils.pp
index 8bddc182a3..d405a379a6 100644
--- a/rtl/os2/sysutils.pp
+++ b/rtl/os2/sysutils.pp
@@ -516,7 +516,7 @@ begin
     FileSeek:=-1;
 end;
 
-function FileSeek (Handle: longint; FOffset, Origin: Int64): Int64;
+function FileSeek (Handle: longint; FOffset: Int64; Origin: Longint): Int64;
 begin
   {$warning need to add 64bit call }
   Result:=FileSeek(Handle,Longint(Foffset),Longint(Origin));
diff --git a/rtl/watcom/sysutils.pp b/rtl/watcom/sysutils.pp
index f32d48799e..acd1b15b4a 100644
--- a/rtl/watcom/sysutils.pp
+++ b/rtl/watcom/sysutils.pp
@@ -226,7 +226,7 @@ begin
 end;
 
 
-Function FileSeek (Handle : Longint; FOffset,Origin : Int64) : Int64;
+Function FileSeek (Handle : Longint; FOffset: Int64; Origin: Longint) : Int64;
 begin
   {$warning need to add 64bit call }
   FileSeek:=FileSeek(Handle,Longint(FOffset),Longint(Origin));
diff --git a/rtl/win/sysutils.pp b/rtl/win/sysutils.pp
index b080048b30..c97de3671a 100644
--- a/rtl/win/sysutils.pp
+++ b/rtl/win/sysutils.pp
@@ -252,7 +252,7 @@ begin
 end;
 
 
-Function FileSeek (Handle : THandle; FOffset,Origin : Int64) : Int64;
+Function FileSeek (Handle : THandle; FOffset: Int64; Origin: Longint) : Int64;
 begin
   if assigned(SetFilePointerEx) then
     begin
diff --git a/rtl/wince/sysutils.pp b/rtl/wince/sysutils.pp
index cd9d6201d5..155a33ecb1 100644
--- a/rtl/wince/sysutils.pp
+++ b/rtl/wince/sysutils.pp
@@ -197,7 +197,7 @@ begin
 end;
 
 
-Function FileSeek (Handle : THandle; FOffset,Origin : Int64) : Int64;
+Function FileSeek (Handle : THandle; FOffset: Int64; Origin: Longint) : Int64;
 begin
   Result := SetFilePointer(Handle, longint(FOffset), nil, longint(Origin));
 end;