diff --git a/mailboxes/boxes-lib.pl b/mailboxes/boxes-lib.pl
index 483ab78cd..08e1e36ba 100755
--- a/mailboxes/boxes-lib.pl
+++ b/mailboxes/boxes-lib.pl
@@ -3074,7 +3074,8 @@ if (&should_switch_to_mail_user()) {
 	&open_as_mail_user(SRC, $src) || return 0;
 	&open_as_mail_user(DST, ">$dst") || return 0;
 	my $buf;
-	while(read(SRC, $buf, 32768) > 0) {
+	my $bs = &get_buffer_size();
+	while(read(SRC, $buf, $bs) > 0) {
 		print DST $buf;
 		}
 	close(SRC);
diff --git a/mailboxes/detach.cgi b/mailboxes/detach.cgi
index 8ba85c064..a9bc8af6e 100755
--- a/mailboxes/detach.cgi
+++ b/mailboxes/detach.cgi
@@ -53,13 +53,14 @@ if ($in{'scale'}) {
 	($jpegin, $jpegout) = &pipeopen("pnmscale $scale 2>/dev/null | cjpeg");
 	print $jpegin $type;
 	print $jpegin $size;
-	while(read($pnmout, $buf, 32768)) {
+	my $bs = &get_buffer_size();
+	while(read($pnmout, $buf, $bs)) {
 		print $jpegin $buf;
 		}
 	close($jpegin);
 	close($pnmout);
 	print "Content-type: image/jpeg\n\n";
-	while(read($jpegout, $buf, 32768)) {
+	while(read($jpegout, $buf, $bs)) {
 		print $buf;
 		}
 	close($jpegout);
diff --git a/mailboxes/detachall.cgi b/mailboxes/detachall.cgi
index 25924bc9f..2f863406d 100755
--- a/mailboxes/detachall.cgi
+++ b/mailboxes/detachall.cgi
@@ -55,7 +55,8 @@ if ($?) {
 # Output the ZIP
 print "Content-type: application/zip\n\n";
 open(ZIP, "<$zip");
-while(read(ZIP, $buf, 32768) > 0) {
+my $bs = &get_buffer_size();
+while(read(ZIP, $buf, $bs) > 0) {
 	print $buf;
 	}
 close(ZIP);
diff --git a/updown/fetch.cgi b/updown/fetch.cgi
index cb6dfcfed..047da9c07 100755
--- a/updown/fetch.cgi
+++ b/updown/fetch.cgi
@@ -53,7 +53,8 @@ if ($ENV{'PATH_INFO'}) {
 		print "Content-type: application/zip\n\n";
 		open(FILE, "<$temp");
 		unlink($temp);
-		while(read(FILE, $buffer, 32768)) {
+		my $bs = &get_buffer_size();
+		while(read(FILE, $buffer, $bs)) {
 			print("$buffer");
 			}
 		close(FILE);
diff --git a/usermin/export_mod.cgi b/usermin/export_mod.cgi
index 5fc1e3ef4..01805a3e4 100755
--- a/usermin/export_mod.cgi
+++ b/usermin/export_mod.cgi
@@ -30,7 +30,8 @@ if ($in{'to'} == 0) {
 	print "Content-type: application/octet-stream\n\n";
 	open(TEMP, "<$temp");
         my $buf;         
-        while(read(TEMP, $buf, 32768)) {
+	my $bs = &get_buffer_size();
+        while(read(TEMP, $buf, $bs)) {
                 print $buf;
                 }
 	close(TEMP);
diff --git a/webmin/export_mod.cgi b/webmin/export_mod.cgi
index 503fa3b5a..26fc9958a 100755
--- a/webmin/export_mod.cgi
+++ b/webmin/export_mod.cgi
@@ -28,7 +28,8 @@ if ($in{'to'} == 0) {
 	print "Content-type: application/x-gzip\n\n";
 	open(TEMP, "<$temp");
 	my $buf;
-	while(read(TEMP, $buf, 32768)) {
+	my $bs = &get_buffer_size();
+	while(read(TEMP, $buf, $bs)) {
 		print $buf;
 		}
 	close(TEMP);