diff --git a/pyproject.toml b/pyproject.toml
index 31d18f8cc..0127b512c 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -68,7 +68,7 @@ requires = [
     'setuptools>=61.2',
     'setuptools_scm>=6.2',
     'cython>=3.0.0,<3.1.0',
-    'numpy',
+    'numpy>=1.25',
     'extension-helpers==1.*',
 ]
 build-backend = 'setuptools.build_meta'
diff --git a/tox.ini b/tox.ini
index d8c8a3d6a..9b1e189f5 100644
--- a/tox.ini
+++ b/tox.ini
@@ -7,16 +7,13 @@ envlist =
     codestyle
     pep517
     bandit
-requires =
-    setuptools >= 61.2
-    pip >= 19.3.1
 isolated_build = true
 
 [testenv]
 # Suppress display of matplotlib plots generated during docs build
 setenv =
     MPLBACKEND=agg
-    devdeps: PIP_EXTRA_INDEX_URL = https://pypi.anaconda.org/scientific-python-nightly-wheels/simple https://pypi.anaconda.org/astropy/simple
+    devdeps: PIP_EXTRA_INDEX_URL = https://pypi.anaconda.org/scientific-python-nightly-wheels/simple https://pypi.anaconda.org/liberfa/simple https://pypi.anaconda.org/astropy/simple
 
 # Pass through the following environment variables which may be needed
 # for the CI
@@ -71,6 +68,7 @@ deps =
     devdeps: scikit-image>=0.0.dev0
     devdeps: scikit-learn>=0.0.dev0
     devdeps: matplotlib>=0.0.dev0
+    devdeps: pyerfa>=0.0.dev0
     devdeps: astropy>=0.0.dev0
     devdeps: git+https://github.com/spacetelescope/gwcs.git
 
@@ -91,6 +89,10 @@ extras =
     alldeps: all
     build_docs: docs
 
+install_command =
+    !devdeps: python -I -m pip install
+    devdeps: python -I -m pip install -v --pre
+
 commands =
     # Force numpy-dev after matplotlib downgrades it
     # (https://github.com/matplotlib/matplotlib/issues/26847)