diff --git a/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_windows.cc b/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_windows.cc
index 9b6a0d5023a..eb71c459e5c 100644
--- a/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_windows.cc
+++ b/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_windows.cc
@@ -251,7 +251,7 @@ class GrpcPolledFdWindows {
     }
   }
 
-  bool IsFdStillReadableLocked() { return GRPC_SLICE_LENGTH(read_buf_) > 0; }
+  bool IsFdStillReadableLocked() { return read_buf_has_data_; }
 
   void ShutdownLocked(grpc_error* error) {
     grpc_winsocket_shutdown(winsocket_);