diff --git a/dlls/uiribbon/main.c b/dlls/uiribbon/main.c
index 9306338086c..a76c349ad96 100644
--- a/dlls/uiribbon/main.c
+++ b/dlls/uiribbon/main.c
@@ -173,13 +173,13 @@ HRESULT WINAPI DllGetClassObject(REFCLSID rclsid, REFIID riid, void **ppv)
          && ! IsEqualGUID( &IID_IUnknown, riid) )
         return E_NOINTERFACE;
 
-    for (i=0; i < sizeof(object_creation)/sizeof(object_creation[0]); i++)
+    for (i = 0; i < ARRAY_SIZE(object_creation); i++)
     {
         if (IsEqualGUID(object_creation[i].clsid, rclsid))
             break;
     }
 
-    if (i == sizeof(object_creation)/sizeof(object_creation[0]))
+    if (i == ARRAY_SIZE(object_creation))
     {
         FIXME("%s: no class found.\n", debugstr_guid(rclsid));
         return CLASS_E_CLASSNOTAVAILABLE;