diff --git a/pyproject.toml b/pyproject.toml
index 84022660..11ddf431 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -19,7 +19,7 @@ classifiers = [
 dependencies = [
     "acme>=2.10",
     "bcrypt>=3.1",
-    "cryptography",
+    "cryptography>=42",
     "ipaddress",
     "pykern",
 ]