diff --git a/Cargo.toml b/Cargo.toml
index 6c4491ba0..eabac34ca 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -18,6 +18,7 @@ edition = "2021"
 keywords = ["ffi"]
 categories = ["development-tools::ffi", "api-bindings"]
 exclude = [ ".github", "book", "tools" ]
+rust-version = "1.77"
 
 # This is stricter about avoiding optional features in dependencies
 # such as 'syn'. We build this way such that CI spots any mistakes