diff --git a/dlls/mapi32/sendmail.c b/dlls/mapi32/sendmail.c
index 9ebb220c032..407dd130411 100644
--- a/dlls/mapi32/sendmail.c
+++ b/dlls/mapi32/sendmail.c
@@ -542,8 +542,8 @@ ULONG WINAPI MAPISendMail( LHANDLE session, ULONG_PTR uiparam,
     }
 
     /* Display an error message since we apparently have no mail clients */
-    LoadStringW(hInstMAPI32, IDS_NO_MAPI_CLIENT, error_msg, sizeof(error_msg) / sizeof(WCHAR));
-    LoadStringW(hInstMAPI32, IDS_SEND_MAIL, msg_title, sizeof(msg_title) / sizeof(WCHAR));
+    LoadStringW(hInstMAPI32, IDS_NO_MAPI_CLIENT, error_msg, ARRAY_SIZE(error_msg));
+    LoadStringW(hInstMAPI32, IDS_SEND_MAIL, msg_title, ARRAY_SIZE(msg_title));
 
     MessageBoxW((HWND) uiparam, error_msg, msg_title, MB_ICONEXCLAMATION);
 
@@ -701,8 +701,8 @@ ULONG WINAPI MAPISendMailW(LHANDLE session, ULONG_PTR uiparam,
     }
 
     /* Display an error message since we apparently have no mail clients */
-    LoadStringW(hInstMAPI32, IDS_NO_MAPI_CLIENT, error_msg, sizeof(error_msg) / sizeof(WCHAR));
-    LoadStringW(hInstMAPI32, IDS_SEND_MAIL, msg_title, sizeof(msg_title) / sizeof(WCHAR));
+    LoadStringW(hInstMAPI32, IDS_NO_MAPI_CLIENT, error_msg, ARRAY_SIZE(error_msg));
+    LoadStringW(hInstMAPI32, IDS_SEND_MAIL, msg_title, ARRAY_SIZE(msg_title));
 
     MessageBoxW((HWND) uiparam, error_msg, msg_title, MB_ICONEXCLAMATION);
 
diff --git a/dlls/mapi32/util.c b/dlls/mapi32/util.c
index 13e4affc39c..9c3b01944a5 100644
--- a/dlls/mapi32/util.c
+++ b/dlls/mapi32/util.c
@@ -903,7 +903,7 @@ BOOL WINAPI FGetComponentPath(LPCSTR component, LPCSTR qualifier, LPSTR dll_path
             char lcid_ver[20];
             UINT i;
 
-            for (i = 0; i < sizeof(fmt)/sizeof(fmt[0]); i++)
+            for (i = 0; i < ARRAY_SIZE(fmt); i++)
             {
                 /* FIXME: what's the correct behaviour here? */
                 if (!qualifier || qualifier == lcid_ver)