commit 187fedd9e1d91ee835b60d6c21a31c85f2eda719
Author: Petr Viktorin <encukou@gmail.com>
Date:   Wed Nov 13 14:35:24 2019 +0100

    Don't pull in importlib_metadata & zipp backports for Python 3.8+
    
    The Python 3.8+ standard library importlib.metadata and zipfile.Path
    are preferred over the backports.

diff --git a/pyproject.toml b/pyproject.toml
index 7c6e1d2..cb2dc76 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -10,8 +10,8 @@ home-page = "https://github.com/pypa/pep517"
 description-file = "README.rst"
 requires = [
     "toml",
-    "importlib_metadata",
-    "zipp",
+    "importlib_metadata;python_version<'3.8'",
+    "zipp;python_version<'3.8'",
 ]
 classifiers = ["License :: OSI Approved :: MIT License"]
 
diff --git a/dev-requirements.txt b/dev-requirements.txt
index 4e62f58..ecbaa9b 100644
--- a/dev-requirements.txt
+++ b/dev-requirements.txt
@@ -4,5 +4,5 @@ mock
 testpath
 toml
 setuptools>=30
-importlib_metadata
-zipp
+importlib_metadata ; python_version<'3.8'
+zipp ; python_version<'3.8'