diff --git a/pyproject.toml b/pyproject.toml
index 0b01c715f..fed528d4a 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,11 +1,3 @@
 [build-system]
-requires = [
-    "setuptools",
-    "wheel",
-    "cython>=0.25",
-    "cymem>=2.0.2,<2.1.0",
-    "preshed>=3.0.2,<3.1.0",
-    "murmurhash>=0.28.0,<1.1.0",
-    "thinc>=7.1.1,<7.2.0",
-]
+requires = ["setuptools"]
 build-backend = "setuptools.build_meta"
diff --git a/setup.cfg b/setup.cfg
index d5de94e5e..9227c9bcb 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -32,6 +32,12 @@ scripts =
 python_requires = >=2.7,!=3.0.*,!=3.1.*,!=3.2.*,!=3.3.*
 setup_requires =
     wheel
+    cython>=0.25
+    # We also need our Cython packages here to compile against
+    cymem>=2.0.2,<2.1.0
+    preshed>=3.0.2,<3.1.0
+    murmurhash>=0.28.0,<1.1.0
+    thinc>=7.1.1,<7.2.0
 install_requires =
     numpy>=1.15.0
     murmurhash>=0.28.0,<1.1.0