diff --git a/dll/win32/oleacc/client.c b/dll/win32/oleacc/client.c
index 5b1f0eee5fb..40e7fbd6539 100644
--- a/dll/win32/oleacc/client.c
+++ b/dll/win32/oleacc/client.c
@@ -168,7 +168,7 @@ static HRESULT WINAPI Client_get_accName(IAccessible *iface, VARIANT varID, BSTR
     if(convert_child_id(&varID) != CHILDID_SELF || !IsWindow(This->hwnd))
         return E_INVALIDARG;
 
-    len = SendMessageW(This->hwnd, WM_GETTEXT, sizeof(name)/sizeof(WCHAR), (LPARAM)name);
+    len = SendMessageW(This->hwnd, WM_GETTEXT, ARRAY_SIZE(name), (LPARAM)name);
     if(!len)
         return S_FALSE;
 
@@ -286,7 +286,7 @@ static HRESULT WINAPI Client_get_accKeyboardShortcut(IAccessible *iface,
     if(convert_child_id(&varID) != CHILDID_SELF)
         return E_INVALIDARG;
 
-    len = SendMessageW(This->hwnd, WM_GETTEXT, sizeof(name)/sizeof(WCHAR), (LPARAM)name);
+    len = SendMessageW(This->hwnd, WM_GETTEXT, ARRAY_SIZE(name), (LPARAM)name);
     for(i=0; i<len; i++) {
         if(name[i] == '&')
             break;
diff --git a/dll/win32/oleacc/main.c b/dll/win32/oleacc/main.c
index ee8a6c03b1c..01ff5752b8f 100644
--- a/dll/win32/oleacc/main.c
+++ b/dll/win32/oleacc/main.c
@@ -109,11 +109,11 @@ static accessible_create get_builtin_accessible_obj(HWND hwnd, LONG objid)
     WCHAR class_name[64];
     int i, idx;
 
-    if(!RealGetWindowClassW(hwnd, class_name, sizeof(class_name)/sizeof(WCHAR)))
+    if(!RealGetWindowClassW(hwnd, class_name, ARRAY_SIZE(class_name)))
         return NULL;
     TRACE("got window class: %s\n", debugstr_w(class_name));
 
-    for(i=0; i<sizeof(builtin_classes)/sizeof(builtin_classes[0]); i++) {
+    for(i=0; i<ARRAY_SIZE(builtin_classes); i++) {
         if(!strcmpiW(class_name, builtin_classes[i].name)) {
             accessible_create ret;
 
@@ -128,7 +128,7 @@ static accessible_create get_builtin_accessible_obj(HWND hwnd, LONG objid)
 
     idx = SendMessageW(hwnd, WM_GETOBJECT, 0, OBJID_QUERYCLASSNAMEIDX);
     if(idx) {
-        for(i=0; i<sizeof(builtin_classes)/sizeof(builtin_classes[0]); i++) {
+        for(i=0; i<ARRAY_SIZE(builtin_classes); i++) {
             if(idx == builtin_classes[i].idx) {
                 accessible_create ret;
 
@@ -172,7 +172,7 @@ HRESULT WINAPI CreateStdAccessibleObject( HWND hwnd, LONG idObject,
 
 HRESULT WINAPI ObjectFromLresult( LRESULT result, REFIID riid, WPARAM wParam, void **ppObject )
 {
-    WCHAR atom_str[sizeof(lresult_atom_prefix)/sizeof(WCHAR)+3*8+3];
+    WCHAR atom_str[ARRAY_SIZE(lresult_atom_prefix)+3*8+3];
     HANDLE server_proc, server_mapping, mapping;
     DWORD proc_id, size;
     IStream *stream;
@@ -193,11 +193,11 @@ HRESULT WINAPI ObjectFromLresult( LRESULT result, REFIID riid, WPARAM wParam, vo
     if(result != (ATOM)result)
         return E_FAIL;
 
-    if(!GlobalGetAtomNameW(result, atom_str, sizeof(atom_str)/sizeof(WCHAR)))
+    if(!GlobalGetAtomNameW(result, atom_str, ARRAY_SIZE(atom_str)))
         return E_FAIL;
     if(memcmp(atom_str, lresult_atom_prefix, sizeof(lresult_atom_prefix)))
         return E_FAIL;
-    p = atom_str + sizeof(lresult_atom_prefix)/sizeof(WCHAR);
+    p = atom_str + ARRAY_SIZE(lresult_atom_prefix);
     proc_id = strtoulW(p, &p, 16);
     if(*p != ':')
         return E_FAIL;
@@ -247,7 +247,7 @@ LRESULT WINAPI LresultFromObject( REFIID riid, WPARAM wParam, LPUNKNOWN pAcc )
     static const WCHAR atom_fmt[] = {'%','0','8','x',':','%','0','8','x',':','%','0','8','x',0};
     static const LARGE_INTEGER seek_zero = {{0}};
 
-    WCHAR atom_str[sizeof(lresult_atom_prefix)/sizeof(WCHAR)+3*8+3];
+    WCHAR atom_str[ARRAY_SIZE(lresult_atom_prefix)+3*8+3];
     IStream *stream;
     HANDLE mapping;
     STATSTG stat;
@@ -320,8 +320,8 @@ LRESULT WINAPI LresultFromObject( REFIID riid, WPARAM wParam, LPUNKNOWN pAcc )
     }
 
     memcpy(atom_str, lresult_atom_prefix, sizeof(lresult_atom_prefix));
-    sprintfW(atom_str+sizeof(lresult_atom_prefix)/sizeof(WCHAR),
-             atom_fmt, GetCurrentProcessId(), HandleToUlong(mapping), stat.cbSize.u.LowPart);
+    sprintfW(atom_str+ARRAY_SIZE(lresult_atom_prefix), atom_fmt, GetCurrentProcessId(),
+             HandleToUlong(mapping), stat.cbSize.u.LowPart);
     atom = GlobalAddAtomW(atom_str);
     if(!atom) {
         CloseHandle(mapping);
diff --git a/media/doc/README.WINE b/media/doc/README.WINE
index 5313ce69e95..3a4fd476f00 100644
--- a/media/doc/README.WINE
+++ b/media/doc/README.WINE
@@ -140,7 +140,7 @@ reactos/dll/win32/objsel              # Synced to WineStaging-3.3
 reactos/dll/win32/odbc32              # Synced to WineStaging-4.0. Depends on port of Linux ODBC.
 reactos/dll/win32/odbccp32            # Synced to WineStaging-4.0
 reactos/dll/win32/ole32               # Synced to WineStaging-4.0
-reactos/dll/win32/oleacc              # Synced to WineStaging-3.3
+reactos/dll/win32/oleacc              # Synced to WineStaging-4.0
 reactos/dll/win32/oleaut32            # Synced to WineStaging-3.3
 reactos/dll/win32/olecli32            # Synced to WineStaging-3.3
 reactos/dll/win32/oledlg              # Synced to WineStaging-3.3