diff --git a/Cargo.toml b/Cargo.toml
index d1f9343..6079d98 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -7,6 +7,7 @@ license = "MIT OR Apache-2.0"
 repository = "https://github.com/extremeandy/streamtools"
 description = "Additional stream combinators"
 readme = "README.md"
+rust-version = "1.65.0"
 
 [dependencies]
 futures = "0.3.28"