diff --git a/textproc/lttoolbox/Makefile b/textproc/lttoolbox/Makefile
index 8a8a77c663ea..4f1c55d45f8d 100644
--- a/textproc/lttoolbox/Makefile
+++ b/textproc/lttoolbox/Makefile
@@ -1,34 +1,34 @@
 # Created by: Mykola Dzham <freebsd@levsha.org.ua>
 
 PORTNAME=	lttoolbox
 PORTVERSION=	${APVER}.${APREV}
 DISTVERSIONPREFIX=	v
-PORTREVISION=	3
 CATEGORIES=	textproc
 
 MAINTAINER=	bofh@FreeBSD.org
 COMMENT=	Tool for lexical, morphological analysis and generation of words
 
 LICENSE=	GPLv2
 
 BUILD_DEPENDS=	utf8cpp>0:devel/utf8cpp
 LIB_DEPENDS=	libicuio.so:devel/icu \
 		libxml2.so:textproc/libxml2
 
 USES=		autoreconf compiler:c++14-lang libtool pathfix pkgconfig
 USE_GITHUB=	yes
 GH_ACCOUNT=	apertium
 USE_LDCONFIG=	yes
 
 APVER=		3.6
-APREV=		1
+APREV=		4
 
 GNU_CONFIGURE=	yes
 
 INSTALL_TARGET=	install-strip
 
 CFLAGS+=	-I${LOCALBASE}/include/utf8cpp
+LDFLAGS+=	-lpthread
 
 PLIST_SUB+=	APVER="${APVER}"
 
 .include <bsd.port.mk>
diff --git a/textproc/lttoolbox/distinfo b/textproc/lttoolbox/distinfo
index 6f5acf2745ca..b165bd7e91c5 100644
--- a/textproc/lttoolbox/distinfo
+++ b/textproc/lttoolbox/distinfo
@@ -1,3 +1,3 @@
-TIMESTAMP = 1647946191
-SHA256 (apertium-lttoolbox-v3.6.1_GH0.tar.gz) = ae45b16591ef160fd111eed6def2fad650e7af35d0c3a924eea7cdc60a44bf1b
-SIZE (apertium-lttoolbox-v3.6.1_GH0.tar.gz) = 185281
+TIMESTAMP = 1651613865
+SHA256 (apertium-lttoolbox-v3.6.4_GH0.tar.gz) = c17802cea31f84144ec225209339b6a0fa541ff2c7c79eabf23482f31872da73
+SIZE (apertium-lttoolbox-v3.6.4_GH0.tar.gz) = 189836
diff --git a/textproc/lttoolbox/pkg-plist b/textproc/lttoolbox/pkg-plist
index 083534b76a6b..227fb59acb79 100644
--- a/textproc/lttoolbox/pkg-plist
+++ b/textproc/lttoolbox/pkg-plist
@@ -1,55 +1,57 @@
+bin/lt-append
 bin/lt-comp
 bin/lt-expand
 bin/lt-print
 bin/lt-proc
 bin/lt-tmxcomp
 bin/lt-tmxproc
 bin/lt-trim
 include/lttoolbox-%%APVER%%/lttoolbox/alphabet.h
 include/lttoolbox-%%APVER%%/lttoolbox/att_compiler.h
 include/lttoolbox-%%APVER%%/lttoolbox/buffer.h
 include/lttoolbox-%%APVER%%/lttoolbox/compiler.h
 include/lttoolbox-%%APVER%%/lttoolbox/compression.h
 include/lttoolbox-%%APVER%%/lttoolbox/deserialiser.h
 include/lttoolbox-%%APVER%%/lttoolbox/entry_token.h
 include/lttoolbox-%%APVER%%/lttoolbox/exception.h
 include/lttoolbox-%%APVER%%/lttoolbox/expander.h
 include/lttoolbox-%%APVER%%/lttoolbox/file_utils.h
 include/lttoolbox-%%APVER%%/lttoolbox/fst_processor.h
 include/lttoolbox-%%APVER%%/lttoolbox/input_file.h
 include/lttoolbox-%%APVER%%/lttoolbox/lt_locale.h
 include/lttoolbox-%%APVER%%/lttoolbox/match_exe.h
 include/lttoolbox-%%APVER%%/lttoolbox/match_node.h
 include/lttoolbox-%%APVER%%/lttoolbox/match_state.h
 include/lttoolbox-%%APVER%%/lttoolbox/my_stdio.h
 include/lttoolbox-%%APVER%%/lttoolbox/node.h
 include/lttoolbox-%%APVER%%/lttoolbox/pattern_list.h
 include/lttoolbox-%%APVER%%/lttoolbox/regexp_compiler.h
 include/lttoolbox-%%APVER%%/lttoolbox/serialiser.h
 include/lttoolbox-%%APVER%%/lttoolbox/sorted_vector.h
 include/lttoolbox-%%APVER%%/lttoolbox/state.h
 include/lttoolbox-%%APVER%%/lttoolbox/string_utils.h
 include/lttoolbox-%%APVER%%/lttoolbox/tmx_compiler.h
 include/lttoolbox-%%APVER%%/lttoolbox/trans_exe.h
 include/lttoolbox-%%APVER%%/lttoolbox/transducer.h
 include/lttoolbox-%%APVER%%/lttoolbox/ustring.h
 include/lttoolbox-%%APVER%%/lttoolbox/xml_parse_util.h
 include/lttoolbox-%%APVER%%/lttoolbox/xml_walk_util.h
 libdata/pkgconfig/lttoolbox.pc
 lib/liblttoolbox3-%%APVER%%.so.1
 lib/liblttoolbox3-%%APVER%%.so.1.0.0
 lib/liblttoolbox3.a
 lib/liblttoolbox3.so
 %%DATADIR%%/acx.rng
 %%DATADIR%%/acx.xsd
 %%DATADIR%%/dix.dtd
 %%DATADIR%%/dix.rnc
 %%DATADIR%%/dix.rng
 %%DATADIR%%/dix.xsd
+man/man1/lt-append.1.gz
 man/man1/lt-comp.1.gz
 man/man1/lt-expand.1.gz
 man/man1/lt-print.1.gz
 man/man1/lt-proc.1.gz
 man/man1/lt-tmxcomp.1.gz
 man/man1/lt-tmxproc.1.gz
 man/man1/lt-trim.1.gz