diff --git a/polish/kadu/Makefile b/polish/kadu/Makefile
index f0e441bb38f0..a76f8b92d13a 100644
--- a/polish/kadu/Makefile
+++ b/polish/kadu/Makefile
@@ -1,70 +1,70 @@
 # Created by: Jacek Pelka <jacek@combit.com.pl>
 
 PORTNAME=	kadu
 PORTVERSION=	4.3
-PORTREVISION=	22
+PORTREVISION=	23
 PORTEPOCH=	1
 CATEGORIES=	polish net-im
 MASTER_SITES=	SF/${PORTNAME}/${PORTNAME}/${PORTVERSION}/:kadu \
 		http://download.kadu.im/stable/:kadu \
 		http://download.kadu.im/additions/:additions
 DISTFILES=	${DISTNAME}${EXTRACT_SUFX}:kadu
 DIST_SUBDIR=	kadu
 EXTRACT_ONLY=	${DISTNAME}${EXTRACT_SUFX}
 
 MAINTAINER=	ports@FreeBSD.org
 COMMENT=	Internet communicator supporting Gadu-Gadu and Jabber/XMPP
 
 LICENSE=	GPLv2
 
 BUILD_DEPENDS=	bash:shells/bash \
 		pl-libgadu>=1.12.2:polish/libgadu
 LIB_DEPENDS=	libmpdclient.so:audio/libmpdclient \
 		libsndfile.so:audio/libsndfile \
 		libinjeqt.so:devel/injeqt \
 		libidn.so:dns/libidn \
 		libqxmpp.so:net-im/qxmpp-qt5 \
 		libgadu.so:polish/libgadu \
 		libgcrypt.so:security/libgcrypt \
 		libotr.so.5:security/libotr \
 		libenchant.so:textproc/enchant
 # TODO ntrack and ntrack-qt (needs porting) ?
 # TODO separate ports for plugins and themes (possible starting with 0.10)
 
 GG6_EMOTS_DISTFILE=	kompatybilne_z_GG6.tar.gz
 GG7_EMOTS_DISTFILE=	dodatkowe_emoty_GG7.tar.gz
 
-USES=		cmake:insource compiler:c++11-lib gettext-runtime gnome \
+USES=		cmake:insource compiler:c++17-lang gettext-runtime gnome \
 		libarchive pkgconfig qca qt:5 readline tar:bzip2 xorg
 USE_XORG=	x11 xext xfixes xscrnsaver
 USE_GNOME=	glib20
 USE_QT=		concurrent core dbus declarative gui multimedia network \
 		script scripttools sql webkit widgets x11extras \
 		xml xmlpatterns buildtools_build linguisttools_build \
 		qmake_build imageformats_run sql-sqlite3_run
 # Setting KADU_VERSION disables git invocation
 CMAKE_ARGS=	-DKADU_VERSION:STRING="${DISTVERSION}" -DWITH_ENCHANT=ON \
 		-DENABLE_TESTS=OFF
 LDFLAGS+=	-lexecinfo
 
 OPTIONS_DEFINE=	GG_EMOTS
 OPTIONS_SUB=	yes
 GG_EMOTS_DESC=	GG-compatible emoticons
 
 GG_EMOTS_DISTFILES=	${GG6_EMOTS_DISTFILE}:additions \
 			${GG7_EMOTS_DISTFILE}:additions
 
 post-patch:
 	@${REINPLACE_CMD} '/kadu_add_test/ s|^|#|' \
 		${WRKSRC}/kadu-core/plugin/CMakeLists.txt
 
 post-install-GG_EMOTS-on:
 	@${MKDIR} ${WRKSRC}/varia/themes/emoticons
 	@cd ${WRKSRC}/varia/themes/emoticons && \
 	${TAR} -zxf ${_DISTDIR}/${GG6_EMOTS_DISTFILE} && \
 	${MV} kompatybilne_z_GG6 gg6_compatible && \
 	cd gg6_compatible && ${TAR} -zxf ${_DISTDIR}/${GG7_EMOTS_DISTFILE}
 	@cd ${WRKSRC}/varia/themes/emoticons && \
 	${COPYTREE_SHARE} gg6_compatible ${STAGEDIR}${DATADIR}/themes/emoticons
 
 .include <bsd.port.mk>
diff --git a/polish/kadu/files/patch-CMakeLists.txt b/polish/kadu/files/patch-CMakeLists.txt
new file mode 100644
index 000000000000..2a96e878a7c6
--- /dev/null
+++ b/polish/kadu/files/patch-CMakeLists.txt
@@ -0,0 +1,23 @@
+--- CMakeLists.txt.orig	2017-01-24 21:36:21 UTC
++++ CMakeLists.txt
+@@ -25,7 +25,11 @@ if (NOT DEFINED CMAKE_CONFIGURATION_TYPES AND NOT CMAK
+ 	set (CMAKE_BUILD_TYPE "${default}" CACHE STRING "Choose the type of build, options are: None(CMAKE_CXX_FLAGS or CMAKE_C_FLAGS used) Debug Release RelWithDebInfo MinSizeRel." FORCE)
+ endif ()
+ 
+-# C++14 support, warnings and other flags
++# C++17 support, warnings and other flags
++#
++# 17 is needed for std::optional, in qxmpp
++set (CMAKE_CXX_STANDARD 17)
++set (CMAKE_CXX_STANDARD_REQUIRED ON)
+ 
+ set (DEFINITIONS QT_NO_CAST_TO_ASCII QT_DISABLE_DEPRECATED_BEFORE=0x040900)
+ list (APPEND DEFINITIONS KADU_EXPORT_TESTS)
+@@ -38,7 +42,6 @@ else ()
+ 	set (COMMON_COMPILE_FLAGS "-Wall -Wextra -Wundef -Wunused -Wuninitialized -Wcast-align -Wpointer-arith -fno-common")
+ 	set (C_FLAGS "-Wwrite-strings")
+ 	set (CXX_FLAGS "-Woverloaded-virtual -Wnon-virtual-dtor ${CXX_FLAGS}")
+-	set (CMAKE_CXX_STANDARD 14)
+ 
+ 	if (NOT WIN32)
+ 		set (COMMON_COMPILE_FLAGS "${COMMON_COMPILE_FLAGS} -fvisibility=hidden")
diff --git a/polish/kadu/files/patch-cmake_KaduMacros.cmake b/polish/kadu/files/patch-cmake_KaduMacros.cmake
new file mode 100644
index 000000000000..310b7839c1d2
--- /dev/null
+++ b/polish/kadu/files/patch-cmake_KaduMacros.cmake
@@ -0,0 +1,12 @@
+--- cmake/KaduMacros.cmake.orig	2021-04-03 20:24:23 UTC
++++ cmake/KaduMacros.cmake
+@@ -44,7 +44,8 @@ include_directories (${INJEQT_INCLUDEDIR})
+ link_directories (${INJEQT_LIBRARY_DIRS})
+ 
+ set (CMAKE_CXX_FLAGS "-Woverloaded-virtual -Wnon-virtual-dtor ${CMAKE_CXX_FLAGS}")
+-set (CMAKE_CXX_STANDARD 14)
++set (CMAKE_CXX_STANDARD 17)
++set (CMAKE_CXX_STANDARD_REQUIRED ON)
+ 
+ if (NOT WIN32)
+     set (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fvisibility-inlines-hidden")