diff --git a/.github/workflows/CI.yaml b/.github/workflows/CI.yaml
index 4005afa5..d3847049 100644
--- a/.github/workflows/CI.yaml
+++ b/.github/workflows/CI.yaml
@@ -44,6 +44,7 @@ jobs:
       - name: Upgrade pip and install doc requirements
         run: |
           python -m pip install --upgrade pip
+          python -m pip install numpy~=1.0
           python -m pip install -e ".[all,docs]"
       - name: build documentation
         run: |
diff --git a/README.rst b/README.rst
index 4ecb81c2..ef3fb652 100644
--- a/README.rst
+++ b/README.rst
@@ -2,7 +2,7 @@
 anesthetic: nested sampling post-processing
 ===========================================
 :Authors: Will Handley and Lukas Hergt
-:Version: 2.9.0
+:Version: 2.9.1
 :Homepage: https://github.com/handley-lab/anesthetic
 :Documentation: http://anesthetic.readthedocs.io/
 
diff --git a/anesthetic/_version.py b/anesthetic/_version.py
index 387cfacc..b03f5b5d 100644
--- a/anesthetic/_version.py
+++ b/anesthetic/_version.py
@@ -1 +1 @@
-__version__ = '2.9.0'
+__version__ = '2.9.1'
diff --git a/anesthetic/plot.py b/anesthetic/plot.py
index 05bedacf..f080ab3a 100644
--- a/anesthetic/plot.py
+++ b/anesthetic/plot.py
@@ -9,6 +9,7 @@
 to create a set of axes and legend proxies.
 
 """
+from packaging import version
 import numpy as np
 from pandas import Series, DataFrame
 import matplotlib.pyplot as plt
@@ -839,7 +840,11 @@ def fastkde_plot_1d(ax, data, *args, **kwargs):
     p /= p.max()
     i = ((x > quantile(x, q[0], p)) & (x < quantile(x, q[-1], p)))
 
-    area = np.trapz(x=x[i], y=p[i]) if density else 1
+    if version.parse(np.__version__) >= version.parse("2.0.0"):
+        trapezoid = np.trapezoid
+    else:
+        trapezoid = np.trapz
+    area = trapezoid(x=x[i], y=p[i]) if density else 1
     if ax.get_xaxis().get_scale() == 'log':
         x = 10**x
     ans = ax.plot(x[i], p[i]/area, color=color, *args, **kwargs)
@@ -962,7 +967,11 @@ def kde_plot_1d(ax, data, *args, **kwargs):
     bw = np.sqrt(kde.covariance[0, 0])
     pp = cut_and_normalise_gaussian(x, p, bw, xmin=data.min(), xmax=data.max())
     pp /= pp.max()
-    area = np.trapz(x=x, y=pp) if density else 1
+    if version.parse(np.__version__) >= version.parse("2.0.0"):
+        trapezoid = np.trapezoid
+    else:
+        trapezoid = np.trapz
+    area = trapezoid(x=x, y=pp) if density else 1
     if ax.get_xaxis().get_scale() == 'log':
         x = 10**x
     ans = ax.plot(x, pp/area, color=color, *args, **kwargs)
diff --git a/pyproject.toml b/pyproject.toml
index 61a00b37..dbb36b74 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -33,7 +33,7 @@ license = {file = "LICENSE"}
 requires-python = ">=3.8"
 dependencies = [
     "scipy<2.0.0",
-    "numpy<2.0.0",
+    "numpy>=1.26.0,<3.0.0",
     "pandas~=2.2.0",
     "matplotlib>=3.6.1,<3.10.0",
 ]
diff --git a/tests/utils.py b/tests/utils.py
index 8c1c72cd..2dfcd720 100644
--- a/tests/utils.py
+++ b/tests/utils.py
@@ -1,12 +1,12 @@
+from importlib.util import find_spec
 import pytest
-import sys
 
 try:
     import astropy  # noqa: F401
 except ImportError:
     pass
 
-condition = 'astropy' not in sys.modules
+condition = find_spec('astropy') is None
 reason = "requires astropy package"
 raises = ImportError
 astropy_mark_skip = pytest.mark.skipif(condition, reason=reason)
@@ -22,7 +22,7 @@ def skipif_no_astropy(param):
 except ImportError:
     pass
 reason = "requires fastkde package"
-condition = 'fastkde' not in sys.modules
+condition = find_spec('fastkde') is None
 raises = ImportError
 fastkde_mark_skip = pytest.mark.skipif(condition, reason=reason)
 fastkde_mark_xfail = pytest.mark.xfail(condition, raises=raises, reason=reason)
@@ -36,7 +36,7 @@ def skipif_no_fastkde(param):
     import getdist  # noqa: F401
 except ImportError:
     pass
-condition = 'getdist' not in sys.modules
+condition = find_spec('getdist') is None
 reason = "requires getdist package"
 raises = ImportError
 getdist_mark_skip = pytest.mark.skipif(condition, reason=reason)
@@ -65,7 +65,7 @@ def skipif_no_getdist(param):
 except ImportError:
     pass
 
-condition = 'h5py' not in sys.modules
+condition = find_spec('h5py') is None
 reason = "requires h5py package"
 raises = ImportError
 h5py_mark_skip = pytest.mark.skipif(condition, reason=reason)