diff --git a/CHANGELOG.rst b/CHANGELOG.rst
index 9afcbcefc..db99d97d6 100644
--- a/CHANGELOG.rst
+++ b/CHANGELOG.rst
@@ -1,6 +1,14 @@
 Changelog
 =========
 
+.. _v3-4-3:
+
+3.4.3 - 2021-02-08
+~~~~~~~~~~~~~~~~~~
+
+* Specify our supported Rust version (>=1.45.0) in our ``setup.py`` so users
+  on older versions will get a clear error message.
+
 .. _v3-4-2:
 
 3.4.2 - 2021-02-08
diff --git a/setup.py b/setup.py
index 7e19d38e5..1a2269542 100644
--- a/setup.py
+++ b/setup.py
@@ -59,6 +59,7 @@ else:
                 if platform.python_implementation() == "PyPy"
                 else ["pyo3/abi3-py36"]
             ),
+            rust_version=">=1.45.0",
         )
     ]