diff --git a/sdk/include/psdk/winbase.h b/sdk/include/psdk/winbase.h
index f803ff178de..0f653ea835f 100644
--- a/sdk/include/psdk/winbase.h
+++ b/sdk/include/psdk/winbase.h
@@ -3945,6 +3945,11 @@ QueryDepthSList(
 
 #endif /* _SLIST_HEADER_ */
 
+#ifdef __WINESRC__
+/* Wine specific. Basically MultiByteToWideChar for us. */
+WCHAR * CDECL wine_get_dos_file_name(LPCSTR str);
+#endif
+
 #ifdef _MSC_VER
 #pragma warning(pop)
 #endif
diff --git a/sdk/lib/3rdparty/libwine/CMakeLists.txt b/sdk/lib/3rdparty/libwine/CMakeLists.txt
index 809893c3bd9..bed7ca764eb 100644
--- a/sdk/lib/3rdparty/libwine/CMakeLists.txt
+++ b/sdk/lib/3rdparty/libwine/CMakeLists.txt
@@ -1,6 +1,5 @@
 
 include_directories(${REACTOS_SOURCE_DIR}/sdk/include/reactos/wine)
-add_definitions(-D__WINESRC__)
 
 list(APPEND SOURCE
     config.c
@@ -10,12 +9,15 @@ list(APPEND SOURCE
     isnan.c
     loader.c
     ${REACTOS_SOURCE_DIR}/sdk/lib/crt/string/wctype.c
+    path.c
     register.c
 #    string.c implements _stricmp, already shipped with crt
 )
 
 add_library(wine ${SOURCE})
 add_dependencies(wine psdk)
+target_compile_definitions(wine PRIVATE __WINESRC__ _WINE)
 
 add_library(wineldr loader.c)
 add_dependencies(wineldr xdk)
+target_compile_definitions(wineldr PRIVATE __WINESRC__)
diff --git a/sdk/lib/3rdparty/libwine/path.c b/sdk/lib/3rdparty/libwine/path.c
new file mode 100644
index 00000000000..d8f11bdafc5
--- /dev/null
+++ b/sdk/lib/3rdparty/libwine/path.c
@@ -0,0 +1,82 @@
+/* Copyright 1993 Erik Bos
+ * Copyright 1996, 2004 Alexandre Julliard
+ * Copyright 2003 Eric Pouech
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
+ *
+ */
+
+#include <windef.h>
+#include <winbase.h>
+#include <winnls.h>
+
+#include <wine/winternl.h>
+
+#include <wine/debug.h>
+WINE_DEFAULT_DEBUG_CHANNEL(path);
+
+static inline BOOL set_ntstatus( NTSTATUS status )
+{
+    if (status) SetLastError( RtlNtStatusToDosError( status ));
+    return !status;
+}
+
+/***********************************************************************
+ *           wine_get_dos_file_name (KERNEL32.@) Not a Windows API
+ *
+ * Return the full DOS file name for a given Unix path.
+ * Returned buffer must be freed by caller.
+ */
+WCHAR * CDECL wine_get_dos_file_name( LPCSTR str )
+{
+    UNICODE_STRING nt_name;
+    NTSTATUS status;
+    WCHAR *buffer;
+    SIZE_T len = strlen(str) + 1;
+
+    if (str[0] != '/')  /* relative path name */
+    {
+        if (!(buffer = RtlAllocateHeap( GetProcessHeap(), 0, len * sizeof(WCHAR) ))) return NULL;
+        MultiByteToWideChar( CP_UNIXCP, 0, str, len, buffer, len );
+        status = RtlDosPathNameToNtPathName_U_WithStatus( buffer, &nt_name, NULL, NULL );
+        RtlFreeHeap( GetProcessHeap(), 0, buffer );
+        if (!set_ntstatus( status )) return NULL;
+        buffer = nt_name.Buffer;
+        len = nt_name.Length / sizeof(WCHAR) + 1;
+    }
+    else
+    {
+#ifdef __REACTOS__
+        ERR("Got absolute UNIX path name in function wine_get_dos_file_name. This is not UNIX. Please fix the caller!\n");
+        ERR("File name: %s\n", str);
+#else
+        len += 8;  /* \??\unix prefix */
+        if (!(buffer = HeapAlloc( GetProcessHeap(), 0, len * sizeof(WCHAR) ))) return NULL;
+        if (!set_ntstatus( wine_unix_to_nt_file_name( str, buffer, &len )))
+        {
+            HeapFree( GetProcessHeap(), 0, buffer );
+            return NULL;
+        }
+#endif
+    }
+    if (buffer[5] == ':')
+    {
+        /* get rid of the \??\ prefix */
+        /* FIXME: should implement RtlNtPathNameToDosPathName and use that instead */
+        memmove( buffer, buffer + 4, (len - 4) * sizeof(WCHAR) );
+    }
+    else buffer[1] = '\\';
+    return buffer;
+}