diff --git a/lib/syndicate.sh b/lib/syndicate.sh
index 27e057d..c5fa160 100755
--- a/lib/syndicate.sh
+++ b/lib/syndicate.sh
@@ -41,7 +41,7 @@ ds_project() {
     echo "$input" | preserves-tool convert --indent=no --select "$selector" "$@"
 }
 
-# ds_connect_stdio <code>
+# ds_connect_stdio [<code>]
 #
 # Uses stdin for input from our peer, and stdout to send output to our
 # peer, connecting them to fds 5 and 6 respectively before evalutating
@@ -49,12 +49,13 @@ ds_project() {
 #
 ds_connect_stdio() {
     exec 5<&0 6>&1
-    eval "$1"
+    exec </dev/null >&2
+    eval "${1:-:}"
     ds_flush
     ds_mainloop
 }
 
-# ds_connect <addr> <code>
+# ds_connect <addr> [<code>]
 #
 # `addr` should match schema transportAddress.Tcp,
 # transportAddress.Unix, or transportAddress.Stdio. Uses `nc` for the
@@ -67,7 +68,7 @@ ds_connect() {
     case $(ds_project "$addr" ".^") in
         tcp) nc_args="$(ds_project "$addr" ". 0" --output-format=unquoted) $(ds_project "$addr" ". 1")";;
         unix) nc_args="-U $(ds_project "$addr" ". 0" --output-format=unquoted)";;
-        stdio) ds_connect_stdio "$2"; return;;
+        stdio) ds_connect_stdio "${2:-:}"; return;;
         *) echo "ds_connect: address '$addr' not supported"; return 1;;
     esac
 
@@ -76,7 +77,7 @@ ds_connect() {
 
     trap "rm -f $f" 2 EXIT RETURN
     {
-        eval "$2"
+        eval "${2:-:}"
         ds_flush
         ds_mainloop
     } 5< <(nc $nc_args <$f) 6>$f