diff --git a/Cargo.toml b/Cargo.toml
index 9789f8a..43bbec0 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -19,6 +19,7 @@ or XID_Continue properties according to
 Unicode Standard Annex #31.
 """
 exclude = ["/.github/**", "/scripts/*"]
+rust-version = "1.17"
 
 [features]
 default = []