diff --git a/README.md b/README.md
index 8599188..d11268f 100644
--- a/README.md
+++ b/README.md
@@ -11,9 +11,11 @@ in the usual way, either by getting it from pip:
 
     pip3 install wordfreq
 
-or by getting the repository and running its setup.py:
+or by getting the repository and installing it using [poetry][]:
 
-    python3 setup.py install
+    poetry install
+
+[poetry]: https://python-poetry.org/
 
 See [Additional CJK installation](#additional-cjk-installation) for extra
 steps that are necessary to get Chinese, Japanese, and Korean word frequencies.
diff --git a/setup.py b/setup.py
index 9f3c24b..acda219 100755
--- a/setup.py
+++ b/setup.py
@@ -44,7 +44,7 @@ setup(
     long_description=README_contents,
     long_description_content_type='text/markdown',
     packages=['wordfreq'],
-    python_requires='>=3.5',
+    python_requires='>=3.7',
     include_package_data=True,
     install_requires=dependencies,