diff --git a/setup.py b/setup.py
index 0d41a7c4..f688e759 100644
--- a/setup.py
+++ b/setup.py
@@ -48,8 +48,11 @@
 """.format(
     NO_EXTENSIONS_ENV
 )
-REQUIREMENTS = ("numpy >= 1.17.0", "six >= 1.12.0")
-EXTRAS_REQUIRE = {}
+REQUIREMENTS = ("six >= 1.12.0",)
+EXTRAS_REQUIRE = {
+    ':implementation_name == "pypy"': ["numpy == 1.15.4"],
+    ':implementation_name == "cpython"': ["numpy >= 1.17.0"],
+}
 DESCRIPTION = (
     u"Helper for B\u00e9zier Curves, Triangles, and Higher Order Objects"
 )