diff --git a/MANIFEST.in b/MANIFEST.in
index b417b8890fa24..d82e64d0a68b8 100644
--- a/MANIFEST.in
+++ b/MANIFEST.in
@@ -3,6 +3,7 @@ include LICENSE
 include RELEASE.md
 include README.md
 include setup.py
+include pyproject.toml
 
 graft doc
 prune doc/build
diff --git a/doc/source/whatsnew/v0.25.0.rst b/doc/source/whatsnew/v0.25.0.rst
index dacd433f112a5..66e6281dd5175 100644
--- a/doc/source/whatsnew/v0.25.0.rst
+++ b/doc/source/whatsnew/v0.25.0.rst
@@ -423,6 +423,7 @@ Reshaping
 - Bug in :func:`pandas.cut` where large bins could incorrectly raise an error due to an integer overflow (:issue:`26045`)
 - Bug in :func:`DataFrame.sort_index` where an error is thrown when a multi-indexed DataFrame is sorted on all levels with the initial level sorted last (:issue:`26053`)
 - Bug in :meth:`Series.nlargest` treats ``True`` as smaller than ``False`` (:issue:`26154`)
+- Bug in :func:`factorize` when passing an ``ExtensionArray`` with a custom ``na_sentinel`` (:issue:`25696`).
 
 Sparse
 ^^^^^^
@@ -435,8 +436,8 @@ Sparse
 Other
 ^^^^^
 
+- Specify build-time requirement in ``pyproject.toml`` (:issue:`25193`)
 - Removed unused C functions from vendored UltraJSON implementation (:issue:`26198`)
-- Bug in :func:`factorize` when passing an ``ExtensionArray`` with a custom ``na_sentinel`` (:issue:`25696`).
 - Allow :class:`Index` and :class:`RangeIndex` to be passed to numpy ``min`` and ``max`` functions.
 
 
diff --git a/pyproject.toml b/pyproject.toml
new file mode 100644
index 0000000000000..31d766aa357b8
--- /dev/null
+++ b/pyproject.toml
@@ -0,0 +1,9 @@
+# When changing the version numbers here, also adjust them in `setup.py`
+[build-system]
+requires = [
+    "setuptools",
+    "wheel",
+    "Cython >= 0.28.2",  # required for VCS build, optional for released source
+    "numpy==1.13.3; python_version<'3.7'",
+    "numpy==1.14.5; python_version>='3.7'",
+]
diff --git a/setup.py b/setup.py
index cb9d4ace8161e..17680598567f4 100755
--- a/setup.py
+++ b/setup.py
@@ -30,14 +30,17 @@ def is_platform_mac():
     return sys.platform == 'darwin'
 
 
-min_numpy_ver = '1.13.3'
+# When changing the version numbers here, also adjust them in `pyproject.toml`
+numpy_requires = [
+    "numpy>=1.13.3; python_version<'3.7'",
+    "numpy>=1.14; python_version>='3.7'",
+]
 setuptools_kwargs = {
     'install_requires': [
         'python-dateutil >= 2.5.0',
         'pytz >= 2015.4',
-        'numpy >= {numpy_ver}'.format(numpy_ver=min_numpy_ver),
-    ],
-    'setup_requires': ['numpy >= {numpy_ver}'.format(numpy_ver=min_numpy_ver)],
+    ] + numpy_requires,
+    'setup_requires': numpy_requires,
     'zip_safe': False,
 }