[fpc-pascal] Can't create unique type from this type

[Steve Williams]

//----------------------------------------------------------------------------
// D3DXHANDLE:
// -----------
// Handle values used to efficiently reference shader and effect parameters.
// Strings can be used as handles.  However, handles are not always strings.
//----------------------------------------------------------------------------

type
    PD3DXHandle = ^TD3DXHandle;
    TD3DXHandle = type PAnsiChar;


The type declaration "TD3DXHandle = type PAnsiChar" (they are of the 
same type, but not assign compatible) compiles fine in Delphi, but FPC 
gives the error
"d3dx9.pas(1999,31) Error: Can't create unique type from this type"

How do I get this type declaration to compile in FPC?  I am compiling in 
Delphi mode (-Mdelphi) with FPC 1.9.4.

Sly