diff --git a/dlls/user32/winstation.c b/dlls/user32/winstation.c
index 98afc499234..122d8486e1f 100644
--- a/dlls/user32/winstation.c
+++ b/dlls/user32/winstation.c
@@ -290,24 +290,13 @@ HDESK WINAPI OpenDesktopA( LPCSTR name, DWORD flags, BOOL inherit, ACCESS_MASK a
 
 HDESK open_winstation_desktop( HWINSTA hwinsta, LPCWSTR name, DWORD flags, BOOL inherit, ACCESS_MASK access )
 {
-    HANDLE ret = 0;
-    DWORD len = name ? lstrlenW(name) : 0;
-    if (len >= MAX_PATH)
-    {
-        SetLastError( ERROR_FILENAME_EXCED_RANGE );
-        return 0;
-    }
-    SERVER_START_REQ( open_desktop )
-    {
-        req->winsta     = wine_server_obj_handle( hwinsta );
-        req->flags      = flags;
-        req->access     = access;
-        req->attributes = OBJ_CASE_INSENSITIVE | (inherit ? OBJ_INHERIT : 0);
-        wine_server_add_data( req, name, len * sizeof(WCHAR) );
-        if (!wine_server_call_err( req )) ret = wine_server_ptr_handle( reply->handle );
-    }
-    SERVER_END_REQ;
-    return ret;
+    OBJECT_ATTRIBUTES attr;
+    UNICODE_STRING str;
+
+    RtlInitUnicodeString( &str, name );
+    InitializeObjectAttributes( &attr, &str, OBJ_CASE_INSENSITIVE, hwinsta, NULL );
+    if (inherit) attr.Attributes |= OBJ_INHERIT;
+    return NtUserOpenDesktop( &attr, flags, access );
 }
 
 
diff --git a/dlls/win32u/syscall.c b/dlls/win32u/syscall.c
index b4d5d718bf5..12b895eff9a 100644
--- a/dlls/win32u/syscall.c
+++ b/dlls/win32u/syscall.c
@@ -101,6 +101,7 @@ static void * const syscalls[] =
     NtUserGetObjectInformation,
     NtUserGetProcessWindowStation,
     NtUserGetThreadDesktop,
+    NtUserOpenDesktop,
     NtUserOpenInputDesktop,
     NtUserOpenWindowStation,
     NtUserSetObjectInformation,
diff --git a/dlls/win32u/win32u.spec b/dlls/win32u/win32u.spec
index bb800830f3d..1c5a960e59c 100644
--- a/dlls/win32u/win32u.spec
+++ b/dlls/win32u/win32u.spec
@@ -1091,7 +1091,7 @@
 @ stub NtUserNotifyProcessCreate
 @ stub NtUserNotifyWinEvent
 @ stub NtUserOpenClipboard
-@ stub NtUserOpenDesktop
+@ stdcall -syscall NtUserOpenDesktop(ptr long long)
 @ stdcall -syscall NtUserOpenInputDesktop(long long long)
 @ stub NtUserOpenThreadDesktop
 @ stdcall -syscall NtUserOpenWindowStation(ptr long)
diff --git a/dlls/win32u/winstation.c b/dlls/win32u/winstation.c
index 0d0eefcf629..aff16e2a873 100644
--- a/dlls/win32u/winstation.c
+++ b/dlls/win32u/winstation.c
@@ -159,6 +159,30 @@ HDESK WINAPI NtUserCreateDesktopEx( OBJECT_ATTRIBUTES *attr, UNICODE_STRING *dev
     return ret;
 }
 
+/***********************************************************************
+ *           NtUserOpenDesktop   (win32u.@)
+ */
+HDESK WINAPI NtUserOpenDesktop( OBJECT_ATTRIBUTES *attr, DWORD flags, ACCESS_MASK access )
+{
+    HANDLE ret = 0;
+    if (attr->ObjectName->Length >= MAX_PATH * sizeof(WCHAR))
+    {
+        SetLastError( ERROR_FILENAME_EXCED_RANGE );
+        return 0;
+    }
+    SERVER_START_REQ( open_desktop )
+    {
+        req->winsta     = wine_server_obj_handle( attr->RootDirectory );
+        req->flags      = flags;
+        req->access     = access;
+        req->attributes = attr->Attributes;
+        wine_server_add_data( req, attr->ObjectName->Buffer, attr->ObjectName->Length );
+        if (!wine_server_call_err( req )) ret = wine_server_ptr_handle( reply->handle );
+    }
+    SERVER_END_REQ;
+    return ret;
+ }
+
 /***********************************************************************
  *           NtUserCloseDesktop  (win32u.@)
  */
diff --git a/dlls/wow64win/syscall.h b/dlls/wow64win/syscall.h
index a1dc08103d4..1d74d55e032 100644
--- a/dlls/wow64win/syscall.h
+++ b/dlls/wow64win/syscall.h
@@ -87,6 +87,7 @@
     SYSCALL_ENTRY( NtUserCreateWindowStation ) \
     SYSCALL_ENTRY( NtUserGetProcessWindowStation ) \
     SYSCALL_ENTRY( NtUserGetThreadDesktop ) \
+    SYSCALL_ENTRY( NtUserOpenDesktop ) \
     SYSCALL_ENTRY( NtUserOpenInputDesktop ) \
     SYSCALL_ENTRY( NtUserOpenWindowStation ) \
     SYSCALL_ENTRY( NtUserSetObjectInformation ) \
diff --git a/dlls/wow64win/user.c b/dlls/wow64win/user.c
index b20ff3f887b..b497b0edbdf 100644
--- a/dlls/wow64win/user.c
+++ b/dlls/wow64win/user.c
@@ -92,6 +92,19 @@ NTSTATUS WINAPI wow64_NtUserCreateDesktopEx( UINT *args )
     return HandleToUlong( ret );
 }
 
+NTSTATUS WINAPI wow64_NtUserOpenDesktop( UINT *args )
+{
+    OBJECT_ATTRIBUTES32 *attr32 = get_ptr( &args );
+    DWORD flags = get_ulong( &args );
+    ACCESS_MASK access = get_ulong( &args );
+
+    struct object_attr64 attr;
+    HANDLE ret;
+
+    ret = NtUserOpenDesktop( objattr_32to64( &attr, attr32 ), flags, access );
+    return HandleToUlong( ret );
+}
+
 NTSTATUS WINAPI wow64_NtUserCloseDesktop( UINT *args )
 {
     HDESK handle = get_handle( &args );
diff --git a/include/ntuser.h b/include/ntuser.h
index 8687a6bbc59..daac994c84d 100644
--- a/include/ntuser.h
+++ b/include/ntuser.h
@@ -36,6 +36,7 @@ HWINSTA WINAPI NtUserGetProcessWindowStation(void);
 HDESK   WINAPI NtUserGetThreadDesktop( DWORD thread );
 HWINSTA WINAPI NtUserOpenWindowStation( OBJECT_ATTRIBUTES *attr, ACCESS_MASK access );
 BOOL    WINAPI NtUserSetObjectInformation( HANDLE handle, INT index, void *info, DWORD len );
+HDESK   WINAPI NtUserOpenDesktop( OBJECT_ATTRIBUTES *attr, DWORD flags, ACCESS_MASK access );
 HDESK   WINAPI NtUserOpenInputDesktop( DWORD flags, BOOL inherit, ACCESS_MASK access );
 BOOL    WINAPI NtUserSetProcessWindowStation( HWINSTA handle );
 BOOL    WINAPI NtUserSetThreadDesktop( HDESK handle );