diff --git a/.github/workflows/continuous_integration.yml b/.github/workflows/continuous_integration.yml
index 3b9c38048..547790d7d 100644
--- a/.github/workflows/continuous_integration.yml
+++ b/.github/workflows/continuous_integration.yml
@@ -15,7 +15,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: ["pypy-3.11", "3.8", "3.9", "3.10", "3.11", "3.12", "3.13", "3.14"]
+        python-version: ["pypy-3.11", "graalpy-25.0", "3.8", "3.9", "3.10", "3.11", "3.12", "3.13", "3.14"]
         os: [ubuntu-latest, macos-latest, windows-latest]
         include:
           - os: ubuntu-latest
diff --git a/tests/test_arrow.py b/tests/test_arrow.py
index b595e4e21..88883bebd 100644
--- a/tests/test_arrow.py
+++ b/tests/test_arrow.py
@@ -1942,7 +1942,7 @@ def test_all_parameters_specified(self):
 @pytest.mark.usefixtures("time_2013_01_01")
 class TestArrowHumanize:
     def test_granularity(self):
-        assert self.now.humanize(granularity="second") == "just now"
+        assert self.now.humanize(self.now, granularity="second") == "just now"
 
         later1 = self.now.shift(seconds=1)
         assert self.now.humanize(later1, granularity="second") == "just now"
@@ -2038,10 +2038,12 @@ def test_granularity(self):
             self.now.humanize(later108, granularity="years")
 
     def test_multiple_granularity(self):
-        assert self.now.humanize(granularity="second") == "just now"
-        assert self.now.humanize(granularity=["second"]) == "just now"
+        assert self.now.humanize(self.now, granularity="second") == "just now"
+        assert self.now.humanize(self.now, granularity=["second"]) == "just now"
         assert (
-            self.now.humanize(granularity=["year", "month", "day", "hour", "second"])
+            self.now.humanize(
+                self.now, granularity=["year", "month", "day", "hour", "second"]
+            )
             == "in 0 years 0 months 0 days 0 hours and 0 seconds"
         )
 
diff --git a/tox.ini b/tox.ini
index 77f020525..d7997fbd1 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,11 +1,12 @@
 [tox]
 minversion = 3.18.0
-envlist = py{py3,38,39,310,311,312,313,314}
+envlist = py{py3,38,39,310,311,312,313,314},graalpy
 skip_missing_interpreters = true
 
 [gh-actions]
 python =
     pypy-3.11: pypy3
+    graalpy-25.0: graalpy
     3.8: py38
     3.9: py39
     3.10: py310