diff --git a/docs/requirements.txt b/docs/requirements.txt
index 3d086f27..3ec550ce 100644
--- a/docs/requirements.txt
+++ b/docs/requirements.txt
@@ -1,8 +1,8 @@
 # NumPy is required for building `bezier` from source.
-numpy >= 1.25.2
+numpy >= 1.26.4, < 2
 # Sphinx and related are required for building documentation.
-Sphinx >= 6.2.1
+Sphinx >= 7.3.7
 # See: https://github.com/readthedocs/sphinx_rtd_theme/issues/1463
 sphinx-copybutton >= 0.5.2
 sphinx-docstring-typing >= 0.0.4
-sphinx-rtd-theme >= 1.2.2
+sphinx-rtd-theme >= 2.0.0
diff --git a/setup.py b/setup.py
index f86aa688..805f94cc 100644
--- a/setup.py
+++ b/setup.py
@@ -72,7 +72,7 @@
 """.format(
     install_prefix=INSTALL_PREFIX_ENV, no_extension=NO_EXTENSION_ENV
 )
-REQUIREMENTS = ("numpy >= 1.25.2",)
+REQUIREMENTS = ("numpy >= 1.26.4, < 2",)
 # See: https://www.python.org/dev/peps/pep-0508/
 #      Dependency specification for Python Software Packages
 EXTRAS_REQUIRE = {