lib/PublicInbox/DS.pm   | 2 ++
 lib/PublicInbox/IMAP.pm | 2 --
 lib/PublicInbox/NNTP.pm | 2 --
 lib/PublicInbox/POP3.pm | 2 --

diff --git a/lib/PublicInbox/DS.pm b/lib/PublicInbox/DS.pm
index 79f7046f87a4dbfe3732d221ecdbc05976336484..daef9d893d5a555bd0fd5188db57edaacd22c43e 100644
--- a/lib/PublicInbox/DS.pm
+++ b/lib/PublicInbox/DS.pm
@@ -648,6 +648,8 @@ 	$self->close;
     }
 }
 
+sub zflush {} # overridden by NNTPdeflate and IMAPdeflate
+
 sub dwaitpid ($;$$) {
 	my ($pid, $cb, $arg) = @_;
 	if ($in_loop) {
diff --git a/lib/PublicInbox/IMAP.pm b/lib/PublicInbox/IMAP.pm
index 89a278c14e90683395eb16756341d669fb86a84e..f4b08eeed04f3387b364822e22c865d692323fc3 100644
--- a/lib/PublicInbox/IMAP.pm
+++ b/lib/PublicInbox/IMAP.pm
@@ -1271,8 +1271,6 @@ }
 
 sub compressed { undef }
 
-sub zflush {} # overridden by IMAPdeflate
-
 # RFC 4978
 sub cmd_compress ($$$) {
 	my ($self, $tag, $alg) = @_;
diff --git a/lib/PublicInbox/NNTP.pm b/lib/PublicInbox/NNTP.pm
index 533a0c59f9398d67aef89739a806f47bdd1c46d8..f0ee11cb0b97a7889cdee091032fccbf9c47eb84 100644
--- a/lib/PublicInbox/NNTP.pm
+++ b/lib/PublicInbox/NNTP.pm
@@ -968,8 +968,6 @@ 	$self->requeue;
 	undef
 }
 
-sub zflush {} # overridden by NNTPdeflate
-
 sub cmd_xpath ($$) {
 	my ($self, $mid) = @_;
 	return r501 unless $mid =~ $ONE_MSGID;
diff --git a/lib/PublicInbox/POP3.pm b/lib/PublicInbox/POP3.pm
index c368615d6f94143af05be534ae782cdea4b6faad..fcea4bb9d154ae4901b2c8fdc678d2d7481f1cb8 100644
--- a/lib/PublicInbox/POP3.pm
+++ b/lib/PublicInbox/POP3.pm
@@ -55,8 +55,6 @@ 	my ($self, $fmt, @args) = @_;
 	printf { $self->{pop3d}->{out} } $fmt."\n", @args;
 }
 
-sub zflush {} # noop
-
 sub requeue_once ($) {
 	my ($self) = @_;
 	# COMPRESS users all share the same DEFLATE context.