diff --git a/math/vtk9/Makefile b/math/vtk9/Makefile
index 2ec7af56d10f..79f86663ec6f 100644
--- a/math/vtk9/Makefile
+++ b/math/vtk9/Makefile
@@ -1,131 +1,134 @@
 PORTNAME=	vtk
 DISTVERSION=	9.1.0
 PORTREVISION=	7
 CATEGORIES=	math graphics
 MASTER_SITES=	https://vtk.org/files/release/${VTK_SHORT_VER}/
 PKGNAMESUFFIX=	9
 DISTNAME=	${PORTNAME:tu}-${DISTVERSION}
 
 MAINTAINER=	yuri@FreeBSD.org
 COMMENT=	Visualization toolkit
 WWW=		https://vtk.org/
 
 LICENSE=	BSD3CLAUSE
 
 LIB_DEPENDS=	\
 		libexpat.so:textproc/expat2 \
 		libfreetype.so:print/freetype2 \
 		libhdf5.so:science/hdf5 \
 		libnetcdf.so:science/netcdf \
 		libpng.so:graphics/png \
 		libtiff.so:graphics/tiff
 
 USES=		alias cmake compiler:c++11-lang gl jpeg localbase xorg
 USE_LDCONFIG=	${PREFIX}/lib/vtk-${VTK_SHORT_VER}
 USE_XORG=	ice x11 xt xext sm xcursor xfixes xrender
 
 CMAKE_ON=	BUILD_SHARED_LIBS \
 		VTK_INSTALL_NO_DOCUMENTATION \
 		Module_vtkTestingCore Module_vtkTestingRendering
 .for m in expat freetype hdf5 jpeg netcdf png tiff zlib # mpi4py should be here, but this fails, see https://gitlab.kitware.com/vtk/vtk/-/issues/18693
 CMAKE_ON+=	VTK_MODULE_USE_EXTERNAL_VTK_${m}
 .endfor
 CMAKE_ARGS=	-DVTK_INSTALL_LIBRARY_DIR=lib/vtk-${VTK_SHORT_VER} \
 		-DVTK_INSTALL_ARCHIVE_DIR=lib/vtk-${VTK_SHORT_VER} \
 		-DVTK_INSTALL_QT_DIR=/${QT_LIBDIR_REL}/plugins/designer \
 		-DSTAGEDIR=${STAGEDIR}
 		# all build options are documented here: https://gitlab.kitware.com/vtk/vtk/blob/master/Documentation/dev/build.md
 
+# disable finding Qt6
+CMAKE_ON+=	CMAKE_DISABLE_FIND_PACKAGE_Qt6
+
 VTK_SHORT_VER=	${PORTVERSION:R}
 
 DOCSDIR=	${PREFIX}/share/doc/vtk-${VTK_SHORT_VER}
 DATADIR=	${PREFIX}/share/vtk-${VTK_SHORT_VER}
 
 # Options
 OPTIONS_DEFINE=	DESIGNER DOCS MPI OSMESA PYTHON QT5 EXAMPLES
 OPTIONS_DEFAULT=	MPI PYTHON QT5 # vtk python binding is needed by other packages, and is unfortunately is unseparable. It is a candidate to be a subpackage.
 OSMESA_DESC=	Use Mesa for off-screen rendering
 DESIGNER_DESC=	Build the Qt Designer plugin
 OPTIONS_SUB=	yes
 
 # Options groups
 VTK_WRAPS=	JAVA TCLTK
 OPTIONS_GROUP=	WRAPPING
 OPTIONS_GROUP_WRAPPING=${VTK_WRAPS}
 GROUPS_DESC=	Groups
 WRAPPING_DESC=	Wrapping
 .for w in ${VTK_WRAPS}
 $w_DESC=	$w wrapping
 .endfor
 
 PYTHON_USES=		python:3.6+
 PYTHON_CMAKE_BOOL=	VTK_WRAP_PYTHON
 PYTHON_CMAKE_ON=	-DVTK_PYTHON_VERSION=${PYTHON_MAJOR_VER} -DPython3_EXECUTABLE=${PYTHON_CMD}
 PYTHON_VARS=		SUB_FILES=PKG-INFO SUB_LIST=PORTVERSION=${PORTVERSION}
 
 QT5_USES=		qt:5
 QT5_USE=		QT=core,declarative,gui,network,opengl,sql,uiplugin,widgets,x11extras,qmake:build,buildtools:build
 QT5_CMAKE_ON=		-DCMAKE_PREFIX_PATH:STRING=${LOCALBASE}/lib/qt5 \
 			-DVTK_GROUP_ENABLE_Qt:STRING=YES \
 			-DVTK_MODULE_ENABLE_VTK_GUISupportQt:STRING=YES
 
 DESIGNER_CMAKE_BOOL=	QT_DESIGNER_PLUGIN
 DESIGNER_USE=		QT=designer
 DESIGNER_IMPLIES=	QT5
 
 MPI_CMAKE_BOOL=		VTK_USE_MPI
 MPI_LIB_DEPENDS=	libmpi.so:net/mpich
 MPI_CMAKE_ON=		-DMPIEXEC=${LOCALBASE}/mpi/openmpi/bin/mpiexec
 
 OSMESA_CMAKE_ON=	-DVTK_OPENGL_HAS_OSMESA:BOOL=ON \
 			-DOSMESA_INCLUDE_DIR:PATH=${LOCALBASE}/include/Mesa \
 			-DOSMESA_LIBRARY:FILEPATH=${LOCALBASE}/lib/libOSMesa.so \
 			-DOPENGL_gl_LIBRARY:FILEPATH=${LOCALBASE}/lib/libOSMesa.so \
 			-DVTK_USE_X:BOOL=OFF
 OSMESA_LIB_DEPENDS=	libOSMesa.so:graphics/libosmesa
 
 # Wrapping
 JAVA_CATEGORIES=	java
 JAVA_VARS=		USE_JAVA=yes
 JAVA_CMAKE_BOOL=	VTK_WRAP_JAVA Module_vtkWrappingJava
 JAVA_CMAKE_ON=		-DJAVA_INCLUDE_PATH:PATH=${JAVA_HOME}/include \
 			-DJAVA_AWT_LIBRARY:PATH=${JAVA_HOME}/jre/lib/${ARCH}/libjawt.so \
 			-DJAVA_JVM_LIBRARY:PATH=${JAVA_HOME}/jre/lib/${ATCH}/libjava.so
 
 TCLTK_USES=		tk
 TCLTK_CMAKE_BOOL=	VTK_WRAP_TCL VTK_Group_Tk
 TCLTK_CMAKE_ON=		-DTCL_INCLUDE_PATH:PATH=${TCL_INCLUDEDIR} \
 			-DTK_INCLUDE_PATH:PATH=${TK_INCLUDEDIR}  \
 			-DVTK_INSTALL_TCL_DIR=lib/vtk-${VTK_SHORT_VER}
 
 DOCS_CMAKE_BOOL=	BUILD_DOCUMENTATION
 DOCS_BUILD_DEPENDS=	doxygen:devel/doxygen
 
 EXAMPLES_CMAKE_BOOL=	BUILD_EXAMPLES
 
 .include <bsd.port.options.mk>
 
 .if !${PORT_OPTIONS:MOSMESA}
 USES+=		gl
 USE_GL=		gl glu
 .endif
 
 .if ${PORT_OPTIONS:MPYTHON} && ${PORT_OPTIONS:MMPI}
 BUILD_DEPENDS=	${PYTHON_PKGNAMEPREFIX}mpi4py>0:net/py-mpi4py@${PY_FLAVOR}
 RUN_DEPENDS=	${PYTHON_PKGNAMEPREFIX}mpi4py>0:net/py-mpi4py@${PY_FLAVOR}
 .endif
 
 CONFLICTS=	vtk6 vtk8
 
 do-install-PYTHON-on:
 	# cmake doesn't install pip's .egg-info: https://gitlab.kitware.com/vtk/vtk/-/issues/18087
 	@${MKDIR} ${STAGEDIR}${PYTHON_SITELIBDIR}/vtk-${DISTVERSION}-py${PYTHON_VER}.egg-info
 	@${INSTALL_DATA} ${WRKDIR}/PKG-INFO ${STAGEDIR}${PYTHON_SITELIBDIR}/vtk-${DISTVERSION}-py${PYTHON_VER}.egg-info
 	# workaround for: VTK installs mpi4py which makes it to conflict with the standalone mpi4py package, see https://gitlab.kitware.com/vtk/vtk/-/issues/18691
 	@${RM} -r ${STAGEDIR}${PYTHON_SITELIBDIR}/mpi4py
 
 post-install: # autoplist: thousands of files, complex dependencies on options
 	@cd ${STAGEDIR}${PREFIX} && \
 		${FIND} * -type f -or -type l >> ${TMPPLIST}
 
 .include <bsd.port.mk>