diff --git a/dlls/gdi/freetype.c b/dlls/gdi/freetype.c
index be2bf175913..b6b179811ff 100644
--- a/dlls/gdi/freetype.c
+++ b/dlls/gdi/freetype.c
@@ -851,13 +851,16 @@ INT WineEngAddFontResourceEx(LPCWSTR file, DWORD flags, PVOID pdv)
 {
     if (ft_handle)  /* do it only if we have freetype up and running */
     {
-        char unixname[MAX_PATH];
+        char *unixname;
 
         if(flags)
             FIXME("Ignoring flags %lx\n", flags);
 
-        if(wine_get_unix_file_name(file, unixname, sizeof(unixname)))
+        if((unixname = wine_get_unix_file_name(file)))
+        {
             AddFontFileToList(unixname, NULL, FALSE);
+            HeapFree(GetProcessHeap(), 0, unixname);
+        }
     }
     return 1;
 }
@@ -884,7 +887,7 @@ BOOL WineEngInit(void)
     DWORD valuelen, datalen, i = 0, type, dlen, vlen;
     LPVOID data;
     WCHAR windowsdir[MAX_PATH];
-    char unixname[MAX_PATH];
+    char *unixname;
     HANDLE font_mutex;
 
     TRACE("\n");
@@ -958,8 +961,11 @@ BOOL WineEngInit(void)
     /* load in the fonts from %WINDOWSDIR%\\Fonts first of all */
     GetWindowsDirectoryW(windowsdir, sizeof(windowsdir) / sizeof(WCHAR));
     strcatW(windowsdir, fontsW);
-    if(wine_get_unix_file_name(windowsdir, unixname, sizeof(unixname)))
+    if((unixname = wine_get_unix_file_name(windowsdir)))
+    {
         ReadFontDir(unixname, FALSE);
+        HeapFree(GetProcessHeap(), 0, unixname);
+    }
 
     /* now look under HKLM\Software\Microsoft\Windows[ NT]\CurrentVersion\Fonts
        for any fonts not installed in %WINDOWSDIR%\Fonts.  They will have their
@@ -981,8 +987,11 @@ BOOL WineEngInit(void)
             while(RegEnumValueW(hkey, i++, valueW, &vlen, NULL, &type, data,
                                 &dlen) == ERROR_SUCCESS) {
                 if(((LPWSTR)data)[0] && ((LPWSTR)data)[1] == ':')
-                    if(wine_get_unix_file_name((LPWSTR)data, unixname, sizeof(unixname)))
+                    if((unixname = wine_get_unix_file_name((LPWSTR)data)))
+                    {
                         AddFontFileToList(unixname, NULL, FALSE);
+                        HeapFree(GetProcessHeap(), 0, unixname);
+                    }
                 /* reset dlen and vlen */
                 dlen = datalen;
                 vlen = valuelen;
diff --git a/dlls/gdi/printdrv.c b/dlls/gdi/printdrv.c
index 73e5f44be99..8543d6e9b16 100644
--- a/dlls/gdi/printdrv.c
+++ b/dlls/gdi/printdrv.c
@@ -511,7 +511,7 @@ static int CreateSpoolFile(LPCSTR pszOutput)
     }
     else
     {
-	char buffer[MAX_PATH];
+        char *buffer;
         WCHAR psCmdPW[MAX_PATH];
 
         TRACE("Just assume it's a file\n");
@@ -521,12 +521,14 @@ static int CreateSpoolFile(LPCSTR pszOutput)
          * Unix correspondant file name
          */
         MultiByteToWideChar(CP_ACP, 0, psCmdP, -1, psCmdPW, MAX_PATH);
-	wine_get_unix_file_name(psCmdPW, buffer, sizeof(buffer));
-
-        if ((fd = open(buffer, O_CREAT | O_TRUNC | O_WRONLY , 0600)) < 0)
+        if ((buffer = wine_get_unix_file_name(psCmdPW)))
         {
-            ERR("Failed to create spool file '%s' ('%s'). (error %s)\n",
-                buffer, psCmdP, strerror(errno));
+            if ((fd = open(buffer, O_CREAT | O_TRUNC | O_WRONLY , 0600)) < 0)
+            {
+                ERR("Failed to create spool file '%s' ('%s'). (error %s)\n",
+                    buffer, psCmdP, strerror(errno));
+            }
+            HeapFree(GetProcessHeap(), 0, buffer);
         }
     }
     return fd;
diff --git a/dlls/kernel/kernel32.spec b/dlls/kernel/kernel32.spec
index ea9939c320e..973d91b1602 100644
--- a/dlls/kernel/kernel32.spec
+++ b/dlls/kernel/kernel32.spec
@@ -1154,7 +1154,7 @@
 @ varargs __wine_call_from_16_regs()
 
 # Unix files
-@ stdcall wine_get_unix_file_name(wstr ptr long)
+@ cdecl wine_get_unix_file_name(wstr) ntdll.wine_get_unix_file_name
 
 # Init code
 @ cdecl __wine_kernel_init()
diff --git a/dlls/kernel/process.c b/dlls/kernel/process.c
index 67984c8fa01..a41b74f6d06 100644
--- a/dlls/kernel/process.c
+++ b/dlls/kernel/process.c
@@ -893,13 +893,13 @@ void __wine_kernel_init(void)
         ExitProcess(1);
     case BINARY_UNIX_LIB:
         {
-            DOS_FULL_NAME full_name;
+            char *unix_name;
 
             TRACE( "starting Winelib app %s\n", debugstr_w(main_exe_name) );
             CloseHandle( main_exe_file );
             main_exe_file = 0;
-            if (DOSFS_GetFullName( main_exe_name, TRUE, &full_name ) &&
-                wine_dlopen( full_name.long_name, RTLD_NOW, error, sizeof(error) ))
+            if ((unix_name = wine_get_unix_file_name( main_exe_name )) &&
+                wine_dlopen( unix_name, RTLD_NOW, error, sizeof(error) ))
             {
                 static const WCHAR soW[] = {'.','s','o',0};
                 if ((p = strrchrW( main_exe_name, '.' )) && !strcmpW( p, soW ))
@@ -908,6 +908,7 @@ void __wine_kernel_init(void)
                     /* update the unicode string */
                     RtlInitUnicodeString( &peb->ProcessParameters->ImagePathName, main_exe_name );
                 }
+                HeapFree( GetProcessHeap(), 0, unix_name );
                 goto found;
             }
             MESSAGE( "wine: could not load %s: %s\n", debugstr_w(main_exe_name), error );
@@ -1606,8 +1607,7 @@ BOOL WINAPI CreateProcessW( LPCWSTR app_name, LPWSTR cmd_line, LPSECURITY_ATTRIB
 {
     BOOL retv = FALSE;
     HANDLE hFile = 0;
-    const char *unixdir = NULL;
-    DOS_FULL_NAME full_dir;
+    char *unixdir = NULL;
     WCHAR name[MAX_PATH];
     WCHAR *tidy_cmdline, *p, *envW = env;
 
@@ -1629,15 +1629,12 @@ BOOL WINAPI CreateProcessW( LPCWSTR app_name, LPWSTR cmd_line, LPSECURITY_ATTRIB
 
     if (cur_dir)
     {
-        if (DOSFS_GetFullName( cur_dir, TRUE, &full_dir )) unixdir = full_dir.long_name;
+        unixdir = wine_get_unix_file_name( cur_dir );
     }
     else
     {
         WCHAR buf[MAX_PATH];
-        if (GetCurrentDirectoryW(MAX_PATH, buf))
-        {
-            if (DOSFS_GetFullName( buf, TRUE, &full_dir )) unixdir = full_dir.long_name;
-        }
+        if (GetCurrentDirectoryW(MAX_PATH, buf)) unixdir = wine_get_unix_file_name( buf );
     }
 
     if (env && !(flags & CREATE_UNICODE_ENVIRONMENT))  /* convert environment to unicode */
@@ -1715,12 +1712,15 @@ BOOL WINAPI CreateProcessW( LPCWSTR app_name, LPWSTR cmd_line, LPSECURITY_ATTRIB
     case BINARY_UNIX_EXE:
         {
             /* unknown file, try as unix executable */
-            DOS_FULL_NAME full_name;
+            char *unix_name;
 
             TRACE( "starting %s as Unix binary\n", debugstr_w(name) );
 
-            if (DOSFS_GetFullName( name, TRUE, &full_name ))
-                retv = (fork_and_exec( full_name.long_name, tidy_cmdline, envW, unixdir ) != -1);
+            if ((unix_name = wine_get_unix_file_name( name )))
+            {
+                retv = (fork_and_exec( unix_name, tidy_cmdline, envW, unixdir ) != -1);
+                HeapFree( GetProcessHeap(), 0, unix_name );
+            }
         }
         break;
     }
@@ -1729,6 +1729,7 @@ BOOL WINAPI CreateProcessW( LPCWSTR app_name, LPWSTR cmd_line, LPSECURITY_ATTRIB
  done:
     if (tidy_cmdline != cmd_line) HeapFree( GetProcessHeap(), 0, tidy_cmdline );
     if (envW != env) HeapFree( GetProcessHeap(), 0, envW );
+    if (unixdir) HeapFree( GetProcessHeap(), 0, unixdir );
     return retv;
 }
 
diff --git a/dlls/ntdll/directory.c b/dlls/ntdll/directory.c
index 0a7a53b69fb..8caa4b35353 100644
--- a/dlls/ntdll/directory.c
+++ b/dlls/ntdll/directory.c
@@ -915,6 +915,26 @@ done:
 }
 
 
+/***********************************************************************
+ *           wine_get_unix_file_name (NTDLL.@) Not a Windows API
+ *
+ * Return the full Unix file name for a given path.
+ * Returned buffer must be freed by caller.
+ */
+char *wine_get_unix_file_name( LPCWSTR dosW )
+{
+    UNICODE_STRING nt_name;
+    ANSI_STRING unix_name;
+    NTSTATUS status;
+
+    if (!RtlDosPathNameToNtPathName_U( dosW, &nt_name, NULL, NULL )) return NULL;
+    status = DIR_nt_to_unix( &nt_name, &unix_name, FALSE, FALSE );
+    RtlFreeUnicodeString( &nt_name );
+    if (status) return NULL;
+    return unix_name.Buffer;
+}
+
+
 /******************************************************************
  *		RtlDoesFileExists_U   (NTDLL.@)
  */
diff --git a/dlls/ntdll/ntdll.spec b/dlls/ntdll/ntdll.spec
index f4192f28031..5cced80f9d1 100644
--- a/dlls/ntdll/ntdll.spec
+++ b/dlls/ntdll/ntdll.spec
@@ -1123,6 +1123,9 @@
 # signal handling
 @ cdecl __wine_set_signal_handler(long ptr)
 
+# Filesystem
+@ cdecl wine_get_unix_file_name(wstr)
+
 ################################################################
 # Wine dll separation hacks, these will go away, don't use them
 #
diff --git a/dlls/winedos/dosconf.c b/dlls/winedos/dosconf.c
index d3ce816d4b8..a968baa8b63 100644
--- a/dlls/winedos/dosconf.c
+++ b/dlls/winedos/dosconf.c
@@ -478,10 +478,13 @@ DOSCONF *DOSCONF_GetConfig(void)
 
     if ((filename[0] != '*' || filename[1] != '\0') && *filename != '\0')
     {
-        CHAR fullname[MAX_PATH];
+        char *fullname;
 
-        if (wine_get_unix_file_name(filename, fullname, sizeof(fullname)))
+        if ((fullname = wine_get_unix_file_name(filename)))
+        {
             DOSCONF_fd = fopen(fullname, "r");
+            HeapFree( GetProcessHeap(), 0, fullname );
+        }
 
         if (DOSCONF_fd)
         {
diff --git a/files/dos_fs.c b/files/dos_fs.c
index af0e4047fa8..057ea2054de 100644
--- a/files/dos_fs.c
+++ b/files/dos_fs.c
@@ -848,26 +848,6 @@ BOOL DOSFS_GetFullName( LPCWSTR name, BOOL check_last, DOS_FULL_NAME *full )
 }
 
 
-/***********************************************************************
- *           wine_get_unix_file_name (KERNEL32.@) Not a Windows API
- *
- * Return the full Unix file name for a given path.
- */
-BOOL WINAPI wine_get_unix_file_name( LPCWSTR dosW, LPSTR buffer, DWORD len )
-{
-    BOOL ret;
-    DOS_FULL_NAME path;
-
-    ret = DOSFS_GetFullName( dosW, FALSE, &path );
-    if (ret && len)
-    {
-        strncpy( buffer, path.long_name, len );
-        buffer[len - 1] = 0; /* ensure 0 termination */
-    }
-    return ret;
-}
-
-
 /***********************************************************************
  *           MulDiv   (KERNEL32.@)
  * RETURNS
diff --git a/include/winbase.h b/include/winbase.h
index 9c7fcc65c0d..50fb61b979b 100644
--- a/include/winbase.h
+++ b/include/winbase.h
@@ -1988,7 +1988,7 @@ VOID        WINAPI _LeaveSysLevel(SYSLEVEL*);
 
 /* Wine internal functions */
 
-BOOL        WINAPI wine_get_unix_file_name( LPCWSTR dos, LPSTR buffer, DWORD len );
+extern char *wine_get_unix_file_name( LPCWSTR dos );
 
 
 /* a few optimizations for i386/gcc */
diff --git a/programs/winemenubuilder/winemenubuilder.c b/programs/winemenubuilder/winemenubuilder.c
index 8d88ad4047c..2e683a7fa08 100644
--- a/programs/winemenubuilder/winemenubuilder.c
+++ b/programs/winemenubuilder/winemenubuilder.c
@@ -326,13 +326,9 @@ static BOOL ExtractFromEXEDLL(const char *szFileName, int nIndex, const char *sz
 inline static char *get_unix_file_name( const char *dos )
 {
     WCHAR dosW[MAX_PATH];
-    char buffer[MAX_PATH], *ret;
 
     MultiByteToWideChar(CP_ACP, 0, dos, -1, dosW, MAX_PATH);
-    if (!wine_get_unix_file_name( dosW, buffer, sizeof(buffer) )) return NULL;
-    ret = HeapAlloc( GetProcessHeap(), 0, lstrlenA( buffer ) + 1 );
-    lstrcpyA( ret, buffer );
-    return ret;
+    return wine_get_unix_file_name( dosW );
 }
 
 static int ExtractFromICO(const char *szFileName, const char *szXPMFileName)
diff --git a/programs/winepath/winepath.c b/programs/winepath/winepath.c
index 31cc8b24a93..a49f38c012b 100644
--- a/programs/winepath/winepath.c
+++ b/programs/winepath/winepath.c
@@ -36,7 +36,7 @@ static char *progname;
 
 /* Wine specific functions */
 extern BOOL process_init(char *argv[]);
-typedef BOOL (WINAPI *wine_get_unix_file_name_t) ( LPCWSTR dos, LPSTR buffer, DWORD len );
+typedef LPSTR (*wine_get_unix_file_name_t) ( LPCWSTR dos );
 /*
  * handle an option
  */
@@ -162,10 +162,15 @@ int main(int argc, char *argv[])
         }
         if (outputformats & UNIXFORMAT) {
             WCHAR dosW[MAX_PATH];
+            char *unix_name;
 
             MultiByteToWideChar(CP_ACP, 0, argv[i], -1, dosW, MAX_PATH);
-            wine_get_unix_file_name_ptr(dosW, path, sizeof(path));
-            printf("%s\n", path);
+            if ((unix_name = wine_get_unix_file_name_ptr(dosW)))
+            {
+                printf("%s\n", unix_name);
+                HeapFree( GetProcessHeap(), 0, unix_name );
+            }
+            else printf( "\n" );
         }
     }