diff --git a/compiler/rustc_feature/src/unstable.rs b/compiler/rustc_feature/src/unstable.rs
index fbd67657e3b4c..f66c9604cbe0d 100644
--- a/compiler/rustc_feature/src/unstable.rs
+++ b/compiler/rustc_feature/src/unstable.rs
@@ -629,7 +629,7 @@ declare_features! (
     /// Allows unsafe on extern declarations and safety qualifiers over internal items.
     (unstable, unsafe_extern_blocks, "1.80.0", Some(123743)),
     /// Allows unsized fn parameters.
-    (unstable, unsized_fn_params, "1.49.0", Some(48055)),
+    (internal, unsized_fn_params, "1.49.0", Some(48055)),
     /// Allows unsized rvalues at arguments and parameters.
     (incomplete, unsized_locals, "1.30.0", Some(48055)),
     /// Allows unsized tuple coercion.