diff --git a/io.c b/io.c
index 5e4fdd5d95..3b3ce3ff82 100644
--- a/io.c
+++ b/io.c
@@ -11311,6 +11311,11 @@ nogvl_copy_stream_sendfile(struct copy_stream_struct *stp)
 	  case EINVAL:
 #ifdef ENOSYS
 	  case ENOSYS:
+#endif
+#ifdef ENOTSUP
+	  /* some RedHat kernels may return ENOTSUP on an NFS mount.
+	     see also: [Feature #16965] */
+	  case ENOTSUP:
 #endif
             return 0;
 	  case EAGAIN: