diff --git a/src/option_parser.cpp b/src/option_parser.cpp
index a3630862..71ce9ac8 100644
--- a/src/option_parser.cpp
+++ b/src/option_parser.cpp
@@ -143,10 +143,6 @@ _parse_and_process_kv_arg(OptData           *optdata_,
     key = "cache.entry";
   ef(key == "negative_entry")
     key = "cache.negative_entry";
-  ef(key == "async_read" && val.empty())
-    val = "true";
-  ef(key == "sync_read" && val.empty())
-    {key = "async_read", val = "false";}
   ef(key == "noforget" && val.empty())
     {key = "remember-nodes", val = "-1";}