diff --git a/math/py-arviz/Makefile b/math/py-arviz/Makefile
index 21a635d1d3e4..57e2c4263320 100644
--- a/math/py-arviz/Makefile
+++ b/math/py-arviz/Makefile
@@ -1,7 +1,6 @@
 PORTNAME=	arviz
 DISTVERSIONPREFIX=	v
-DISTVERSION=	0.20.0
-PORTREVISION=	1
+DISTVERSION=	0.21.0
 CATEGORIES=	math python
 #MASTER_SITES=	PYPI # missing test files
 PKGNAMEPREFIX=	${PYTHON_PKGNAMEPREFIX}
@@ -15,11 +14,11 @@ LICENSE_FILE=	${WRKSRC}/LICENSE
 
 RUN_DEPENDS=	${PYTHON_PKGNAMEPREFIX}dm-tree>=0.1.8:devel/py-dm-tree@${PY_FLAVOR} \
 		${PYTHON_PKGNAMEPREFIX}matplotlib>=3.5:math/py-matplotlib@${PY_FLAVOR} \
-		${PYTHON_PKGNAMEPREFIX}netCDF4>=1.0.2:science/py-netCDF4@${PY_FLAVOR} \
 		${PYNUMPY} \
 		${PYTHON_PKGNAMEPREFIX}packaging>0:devel/py-packaging@${PY_FLAVOR} \
 		${PYTHON_PKGNAMEPREFIX}pandas>=1.5.0:math/py-pandas@${PY_FLAVOR} \
 		${PYTHON_PKGNAMEPREFIX}scipy>=1.9.0:science/py-scipy@${PY_FLAVOR} \
+		${PYTHON_PKGNAMEPREFIX}h5netcdf>0:science/py-h5netcdf@${PY_FLAVOR} \
 		${PYTHON_PKGNAMEPREFIX}typing-extensions>=4.1.0:devel/py-typing-extensions@${PY_FLAVOR} \
 		${PYTHON_PKGNAMEPREFIX}xarray>=2022.6.0:devel/py-xarray@${PY_FLAVOR} \
 		${PYTHON_PKGNAMEPREFIX}xarray-einstats>=0.3:devel/py-xarray-einstats@${PY_FLAVOR}
@@ -37,7 +36,11 @@ GH_ACCOUNT=	arviz-devs
 
 NO_ARCH=	yes
 
-# 1 error in tests preventing all tests from running: _tkinter.TclError: no display name and no $DISPLAY environment variable
-# see https://github.com/arviz-devs/arviz/issues/2381
+TEST_ENV=	${MAKE_ENV} \
+		PYTHONPATH=${STAGEDIR}${PYTHONPREFIX_SITELIBDIR} \
+		DISPLAY=${DISPLAY} \
+		XAUTHORITY=${XAUTHORITY}
+
+# tests as of 0.21.0: 2928 passed, 31 skipped, 124 warnings, 599 errors in 1751.10s (0:29:11)
 
 .include <bsd.port.mk>
diff --git a/math/py-arviz/distinfo b/math/py-arviz/distinfo
index f7a7dac268ae..632820c200bb 100644
--- a/math/py-arviz/distinfo
+++ b/math/py-arviz/distinfo
@@ -1,3 +1,3 @@
-TIMESTAMP = 1727590231
-SHA256 (arviz-devs-arviz-v0.20.0_GH0.tar.gz) = bf975726756d48e4e57a2a5131b1f9771786b25b8f0e9dbead85fdc1ac017979
-SIZE (arviz-devs-arviz-v0.20.0_GH0.tar.gz) = 9369175
+TIMESTAMP = 1741403489
+SHA256 (arviz-devs-arviz-v0.21.0_GH0.tar.gz) = bc38c9090c33f098232aa390904bea9865aa9f62d600599dcb9ee2a447d54c07
+SIZE (arviz-devs-arviz-v0.21.0_GH0.tar.gz) = 9375621