diff --git a/runtime/bin/eventhandler_win.cc b/runtime/bin/eventhandler_win.cc
index 1a179e2e9814..1683ac7a376e 100644
--- a/runtime/bin/eventhandler_win.cc
+++ b/runtime/bin/eventhandler_win.cc
@@ -148,15 +148,7 @@ void Handle::Close() {
     // If the handle uses synchronous I/O (e.g. stdin), cancel any pending
     // operation before closing the handle, so the read thread is not blocked.
     BOOL result = CancelIoEx(handle_, nullptr);
-// The Dart code 'stdin.listen(() {}).cancel()' causes this assert to be
-// triggered on Windows 7, but not on Windows 10.
-#if defined(DEBUG)
-    if (IsWindows10OrGreater()) {
-      ASSERT(result || (GetLastError() == ERROR_NOT_FOUND));
-    }
-#else
-    USE(result);
-#endif
+    ASSERT(result || (GetLastError() == ERROR_NOT_FOUND));
   }
   if (!IsClosing()) {
     // Close the socket and set the closing state. This close method can be