diff --git a/include/wx/chartype.h b/include/wx/chartype.h
index 3ff445f602..cc65a8b3a8 100644
--- a/include/wx/chartype.h
+++ b/include/wx/chartype.h
@@ -108,7 +108,7 @@
 #elif defined(__BORLANDC__) && (__BORLANDC__ >= 0x520)
     #define wxHAVE_TCHAR_SUPPORT
     #include <ctype.h>
-#elif defined(__MINGW32__) && wxCHECK_W32API_VERSION( 1, 0 )
+#elif defined(__MINGW32__)
     #define wxHAVE_TCHAR_SUPPORT
     #include <stddef.h>
     #include <string.h>
diff --git a/include/wx/filefn.h b/include/wx/filefn.h
index 3eafe3e781..c75d309e36 100644
--- a/include/wx/filefn.h
+++ b/include/wx/filefn.h
@@ -127,8 +127,7 @@ enum wxPosixPermissions
       ( \
         defined(__VISUALC__) || \
         defined(__MINGW64_TOOLCHAIN__) || \
-        (defined(__MINGW32__) && !defined(__WINE__) && \
-                                wxCHECK_W32API_VERSION(0, 5)) || \
+        (defined(__MINGW32__) && !defined(__WINE__)) || \
         defined(__BORLANDC__) \
       )
 
diff --git a/include/wx/msw/gccpriv.h b/include/wx/msw/gccpriv.h
index 319b98746b..d0b47e4183 100644
--- a/include/wx/msw/gccpriv.h
+++ b/include/wx/msw/gccpriv.h
@@ -100,46 +100,6 @@
     #define __CYGWIN10__
 #endif
 
-/* Mingw runtime 1.0-20010604 has some missing _tXXXX functions,
-   so let's define them ourselves: */
-#if defined(__GNUWIN32__) && wxCHECK_W32API_VERSION( 1, 0 ) \
-    && !wxCHECK_W32API_VERSION( 1, 1 )
-    #ifndef _tsetlocale
-      #if wxUSE_UNICODE
-      #define _tsetlocale _wsetlocale
-      #else
-      #define _tsetlocale setlocale
-      #endif
-    #endif
-    #ifndef _tgetenv
-      #if wxUSE_UNICODE
-      #define _tgetenv _wgetenv
-      #else
-      #define _tgetenv getenv
-      #endif
-    #endif
-    #ifndef _tfopen
-      #if wxUSE_UNICODE
-      #define _tfopen _wfopen
-      #else
-      #define _tfopen fopen
-      #endif
-    #endif
-#endif
-
-/* current (= before mingw-runtime 3.3) mingw32 headers forget to
-   define _puttchar, this will probably be fixed in the next versions but
-   for now do it ourselves
- */
-#if defined( __MINGW32__ ) && \
-        !wxCHECK_MINGW32_VERSION(3,3) && !defined( _puttchar )
-    #ifdef wxUSE_UNICODE
-        #define  _puttchar   putwchar
-    #else
-        #define  _puttchar   puttchar
-    #endif
-#endif
-
 /*
     Traditional MinGW (but not MinGW-w64 nor TDM-GCC) omits many POSIX
     functions from their headers when compiled with __STRICT_ANSI__ defined.
diff --git a/include/wx/msw/missing.h b/include/wx/msw/missing.h
index f289deab16..1b09f730e9 100644
--- a/include/wx/msw/missing.h
+++ b/include/wx/msw/missing.h
@@ -246,27 +246,6 @@
 #ifndef TVM_SETBKCOLOR
     #define TVM_SETBKCOLOR          (TV_FIRST + 29)
     #define TVM_SETTEXTCOLOR        (TV_FIRST + 30)
-#endif
-
- /*
-  * The following are specifically required for MinGW.
-  */
-
-#if defined (__MINGW32__)
-
-#if !wxCHECK_W32API_VERSION(3,1)
-
-#include <windows.h>
-#include "wx/msw/winundef.h"
-
-typedef struct
-{
-    RECT       rgrc[3];
-    WINDOWPOS *lppos;
-} NCCALCSIZE_PARAMS, *LPNCCALCSIZE_PARAMS;
-
-#endif
-
 #endif
 
 // Various defines used by the webview library that are needed by mingw 
diff --git a/include/wx/msw/winundef.h b/include/wx/msw/winundef.h
index 8d86f0cc7a..b363e7e94e 100644
--- a/include/wx/msw/winundef.h
+++ b/include/wx/msw/winundef.h
@@ -252,15 +252,6 @@
 #ifdef StartDoc
    #undef StartDoc
 
-   // Work around a bug in very old MinGW headers that didn't define DOCINFOW
-   // and DOCINFOA but only DOCINFO in both ANSI and Unicode.
-   #if defined( __GNUG__ )
-      #if !wxCHECK_W32API_VERSION( 0, 5 )
-        #define DOCINFOW DOCINFO
-        #define DOCINFOA DOCINFO
-      #endif
-   #endif
-
    #ifdef _UNICODE
    inline int StartDoc(HDC h, CONST DOCINFOW* info)
    {
diff --git a/src/common/filename.cpp b/src/common/filename.cpp
index 7eda5ae42c..a733643d71 100644
--- a/src/common/filename.cpp
+++ b/src/common/filename.cpp
@@ -1650,12 +1650,7 @@ bool wxFileName::GetShortcutTarget(const wxString& shortcutPath,
             if (SUCCEEDED(hres))
             {
                 wxChar buf[2048];
-                // Wrong prototype in early versions
-#if defined(__MINGW32__) && !wxCHECK_W32API_VERSION(2, 2)
-                psl->GetPath((CHAR*) buf, 2048, NULL, SLGP_UNCPRIORITY);
-#else
                 psl->GetPath(buf, 2048, NULL, SLGP_UNCPRIORITY);
-#endif
                 targetFilename = wxString(buf);
                 success = (shortcutPath != targetFilename);
 
diff --git a/src/msw/dialup.cpp b/src/msw/dialup.cpp
index 5ff78e7c7e..c38af22209 100644
--- a/src/msw/dialup.cpp
+++ b/src/msw/dialup.cpp
@@ -49,7 +49,6 @@ wxDEFINE_EVENT( wxEVT_DIALUP_DISCONNECTED, wxDialUpEvent );
 // Doesn't yet compile under BC++
 // Wine: no wininet.h
 #if (!defined(__BORLANDC__) || (__BORLANDC__>=0x550)) && \
-    (!defined(__GNUWIN32__) || wxCHECK_W32API_VERSION(0, 5)) && \
     !defined(__WINE__)
 
 #include <ras.h>
diff --git a/src/msw/listctrl.cpp b/src/msw/listctrl.cpp
index ad7db78eba..ba30bd6e05 100644
--- a/src/msw/listctrl.cpp
+++ b/src/msw/listctrl.cpp
@@ -393,12 +393,10 @@ WXDWORD wxListCtrl::MSWGetStyle(long style, WXDWORD *exstyle) const
     else if ( style & wxLC_SORT_DESCENDING )
         wstyle |= LVS_SORTDESCENDING;
 
-#if !( defined(__GNUWIN32__) && !wxCHECK_W32API_VERSION( 1, 0 ) )
     if ( style & wxLC_VIRTUAL )
     {
         wstyle |= LVS_OWNERDATA;
     }
-#endif // ancient cygwin
 
     return wstyle;
 }