diff --git a/.github/workflows/coverage.yml b/.github/workflows/coverage.yml
index 41327d3a..1dfedb67 100644
--- a/.github/workflows/coverage.yml
+++ b/.github/workflows/coverage.yml
@@ -9,7 +9,7 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-24.04]
-        python-version: [pypy3.11, "graalpy-25.0", "3.x"]
+        python-version: [pypy3.11, "graalpy-25.1", "3.x"]
     steps:
       - uses: actions/checkout@v7
         with:
diff --git a/README.rst b/README.rst
index 2c38eb81..425cd689 100644
--- a/README.rst
+++ b/README.rst
@@ -11,7 +11,7 @@ functions, compatible with the Python stdlib's submodule `math.integer
 <https://docs.python.org/3.15/library/math.integer.html>`_.
 
 This module requires Python 3.11 or later versions and has been tested with
-CPython 3.11 through 3.15, with PyPy3.11 7.3.23 and with GraalPy 25.0.3.
+CPython 3.11 through 3.15, with PyPy3.11 7.3.23 and with GraalPy 25.1.3.
 Free-threading builds of the CPython are supported.
 
 Releases are available in the Python Package Index (PyPI) at
diff --git a/tests/test_functions.py b/tests/test_functions.py
index d89efc3c..9b4f49e7 100644
--- a/tests/test_functions.py
+++ b/tests/test_functions.py
@@ -236,7 +236,7 @@ def test_interfaces():
 
 
 @pytest.mark.skipif(platform.python_implementation() == "GraalVM",
-                    reason="oracle/graalpython#593")
+                    reason="oracle/graalpython#998")
 def test_func_api():
     for fn in ["comb", "factorial", "gcd", "isqrt", "lcm", "perm"]:
         f = getattr(math, fn)
diff --git a/tests/test_mpz.py b/tests/test_mpz.py
index ab89ca49..31b88d2f 100644
--- a/tests/test_mpz.py
+++ b/tests/test_mpz.py
@@ -452,10 +452,6 @@ def test_add_int_subclasses():
 def test_binary_mixed(x, y):
     mx = mpz(x)
     for op in [operator.add, operator.mul, operator.sub]:
-        if (platform.python_implementation() == "GraalVM"
-                and op in [operator.add, operator.sub]
-                and str(y.imag) == "-0.0"):
-            continue  # issue oracle/graalpython#585
         assert str(op(mx, y)) == str(op(x, y))
         assert str(op(y, mx)) == str(op(y, x))
         if op != operator.sub:
@@ -712,8 +708,6 @@ def test_power_errors():
         pow(mpz(10**1000), 1j)
     with pytest.raises(TypeError):
         pow(object(), mpz(321))
-    if platform.python_implementation() == "GraalVM":
-        return  # issue oracle/graalpython#551
     with pytest.raises(OverflowError):
         pow(mpz(2), mpz(1<<64))
     if BITCNT_MAX < (1<<64) - 1:
@@ -814,8 +808,6 @@ def test_methods(x):
         assert meth(mx) == meth(x)
 
 
-@pytest.mark.skipif(platform.python_implementation() == "GraalVM",
-                    reason="oracle/graalpython#883")
 @given(bigints(), integers(min_value=0, max_value=10000),
        sampled_from(["big", "little"]), booleans())
 @example(0, 0, "big", False)
@@ -840,6 +832,7 @@ def test_methods(x):
 @example(128, 1, "big", False)
 @example(-32383289396013590652, 0, "big", True)
 @example(-384, 1, "big", True)
+@example(32768, 2, "big", True)
 def test_to_bytes_bulk(x, length, byteorder, signed):
     try:
         rx = x.to_bytes(length, byteorder, signed=signed)
@@ -951,12 +944,14 @@ def test_from_bytes_interface():
 @example(1<<116)
 @example(646541478744828163276576707651635923929979156076518566789121)
 @example((0xfffffffffffff8<<(242*4)) + (1<<970))
+@example(0xa<<10000)
 def test_to_float(x):
     mx = mpz(x)
     try:
         fx = float(x)
     except OverflowError:
-        pytest.raises(OverflowError, lambda: float(mx))
+        with pytest.raises(OverflowError):
+            float(mx)
     else:
         assert str(float(mx)) == str(fx)