diff --git a/dlls/user32/class.c b/dlls/user32/class.c
index 5d97823dc84..dec82b5b775 100644
--- a/dlls/user32/class.c
+++ b/dlls/user32/class.c
@@ -573,8 +573,15 @@ ATOM WINAPI RegisterClassExW( const WNDCLASSEXW* wc )
  */
 BOOL WINAPI UnregisterClassA( LPCSTR className, HINSTANCE hInstance )
 {
-    ATOM atom = HIWORD(className) ? GlobalFindAtomA( className ) : LOWORD(className);
-    return UnregisterClassW( (LPCWSTR)MAKEINTATOM(atom), hInstance );
+    if (!IS_INTRESOURCE(className))
+    {
+        WCHAR name[MAX_ATOM_LEN + 1];
+
+        if (!MultiByteToWideChar( CP_ACP, 0, className, -1, name, MAX_ATOM_LEN + 1 ))
+            return FALSE;
+        return UnregisterClassW( name, hInstance );
+    }
+    return UnregisterClassW( (LPCWSTR)className, hInstance );
 }
 
 /***********************************************************************
@@ -583,20 +590,14 @@ BOOL WINAPI UnregisterClassA( LPCSTR className, HINSTANCE hInstance )
 BOOL WINAPI UnregisterClassW( LPCWSTR className, HINSTANCE hInstance )
 {
     CLASS *classPtr = NULL;
-    ATOM atom = HIWORD(className) ? GlobalFindAtomW( className ) : LOWORD(className);
 
-    TRACE("%s %p %x\n",debugstr_w(className), hInstance, atom);
-
-    if (!atom)
-    {
-        SetLastError( ERROR_CLASS_DOES_NOT_EXIST );
-        return FALSE;
-    }
+    TRACE("%s %p\n",debugstr_w(className), hInstance);
 
     SERVER_START_REQ( destroy_class )
     {
-        req->atom = atom;
         req->instance = hInstance;
+        if (IS_INTRESOURCE(className)) req->atom = LOWORD(className);
+        else wine_server_add_data( req, className, strlenW(className)*sizeof(WCHAR) );
         if (!wine_server_call_err( req )) classPtr = reply->client_ptr;
     }
     SERVER_END_REQ;
diff --git a/include/wine/server_protocol.h b/include/wine/server_protocol.h
index da3c45ba5f7..8d1485e173c 100644
--- a/include/wine/server_protocol.h
+++ b/include/wine/server_protocol.h
@@ -3609,6 +3609,7 @@ struct destroy_class_request
     struct request_header __header;
     atom_t         atom;
     void*          instance;
+    /* VARARG(name,unicode_str); */
 };
 struct destroy_class_reply
 {
@@ -4882,6 +4883,6 @@ union generic_reply
     struct set_completion_info_reply set_completion_info_reply;
 };
 
-#define SERVER_PROTOCOL_VERSION 325
+#define SERVER_PROTOCOL_VERSION 326
 
 #endif /* __WINE_WINE_SERVER_PROTOCOL_H */
diff --git a/server/class.c b/server/class.c
index ff39dc06266..334542ed7e2 100644
--- a/server/class.c
+++ b/server/class.c
@@ -186,9 +186,13 @@ DECL_HANDLER(create_class)
 /* destroy a window class */
 DECL_HANDLER(destroy_class)
 {
-    struct window_class *class = find_class( current->process, req->atom, req->instance );
+    struct window_class *class;
+    atom_t atom = req->atom;
 
-    if (!class)
+    if (get_req_data_size())
+        atom = find_global_atom( NULL, get_req_data(), get_req_data_size() / sizeof(WCHAR) );
+
+    if (!(class = find_class( current->process, atom, req->instance )))
         set_win32_error( ERROR_CLASS_DOES_NOT_EXIST );
     else if (class->count)
         set_win32_error( ERROR_CLASS_HAS_WINDOWS );
diff --git a/server/protocol.def b/server/protocol.def
index aa06bd5ed0f..f2e33ef60d5 100644
--- a/server/protocol.def
+++ b/server/protocol.def
@@ -2610,6 +2610,7 @@ enum message_type
 @REQ(destroy_class)
     atom_t         atom;           /* class atom */
     void*          instance;       /* module instance */
+    VARARG(name,unicode_str);      /* class name */
 @REPLY
     void*          client_ptr;     /* pointer to class in client address space */
 @END
diff --git a/server/trace.c b/server/trace.c
index 3d5a3c54366..a6d3ee5147f 100644
--- a/server/trace.c
+++ b/server/trace.c
@@ -3205,7 +3205,9 @@ static void dump_create_class_reply( const struct create_class_reply *req )
 static void dump_destroy_class_request( const struct destroy_class_request *req )
 {
     fprintf( stderr, " atom=%04x,", req->atom );
-    fprintf( stderr, " instance=%p", req->instance );
+    fprintf( stderr, " instance=%p,", req->instance );
+    fprintf( stderr, " name=" );
+    dump_varargs_unicode_str( cur_size );
 }
 
 static void dump_destroy_class_reply( const struct destroy_class_reply *req )