diff --git a/dlls/kernel32/sync.c b/dlls/kernel32/sync.c
index 8ee0e718c0b..7c15fd800dd 100644
--- a/dlls/kernel32/sync.c
+++ b/dlls/kernel32/sync.c
@@ -1701,7 +1701,7 @@ HANDLE WINAPI CreateMailslotW( LPCWSTR lpName, DWORD nMaxMessageSize,
     else
         timeout.QuadPart = ((LONGLONG)0x7fffffff << 32) | 0xffffffff;
 
-    status = NtCreateMailslotFile( &handle, GENERIC_READ | GENERIC_WRITE, &attr,
+    status = NtCreateMailslotFile( &handle, GENERIC_READ | SYNCHRONIZE, &attr,
                                    &iosb, 0, 0, nMaxMessageSize, &timeout );
     if (status)
     {