lib/PublicInbox/ProcessPipe.pm | 4 ++--

diff --git a/lib/PublicInbox/ProcessPipe.pm b/lib/PublicInbox/ProcessPipe.pm
index 400a22f3bf65a0a6eda398cee101d34c9fcb373a..e540dc220564160e7d012f3f1f0932053a3f4698 100644
--- a/lib/PublicInbox/ProcessPipe.pm
+++ b/lib/PublicInbox/ProcessPipe.pm
@@ -5,7 +5,6 @@ # a tied handle for auto reaping of children tied to a pipe, see perltie(1)
 package PublicInbox::ProcessPipe;
 use strict;
 use v5.10.1;
-use PublicInbox::DS qw(dwaitpid);
 use Carp qw(carp);
 
 sub TIEHANDLE {
@@ -48,7 +47,8 @@ 		} else {
 			carp "waitpid($pid, 0) = $wp, \$!=$!, \$?=$?";
 		}
 	} else { # caller just undef-ed it, let event loop deal with it
-		dwaitpid $pid, $cb, $arg;
+		require PublicInbox::DS;
+		PublicInbox::DS::dwaitpid($pid, $cb, $arg);
 	}
 	$ret;
 }