diff --git a/Cargo.toml b/Cargo.toml
index 9deb2ac564e9..107ee46ea390 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -135,7 +135,7 @@ cargo-args = ["-Zbuild-std=core"]
 rustc-std-workspace-core = { version = "1.0.0", optional = true }
 
 [features]
-default = ["std"]
+default = ["const-extern-fn", "std"]
 std = []
 rustc-dep-of-std = ["rustc-std-workspace-core"]
 extra_traits = []