[Mingw-msys] _imp__HttpOpen@20

[Lennart B. <len...@st...>]

I am trying to compile a small program using HttpOpen with MinGW. I have 
created the library file:

    pexports winhttp.dll | sed "s/^_//" > winhttp.def
    winhttp.a   dlltool -U -d winhttp.def -l winhttp.a
    gcc test.c -L. -lwinhttp

I get the error

   ccUjbaaa.o(.text+0x6d):test.c: undefined reference to 
`_imp__WinHttpOpen@20'

What should I do to fix this?