diff --git a/Cargo.toml b/Cargo.toml
index 234e74453472..6d15865ab684 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -137,7 +137,7 @@ 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 = ['align', 'rustc-std-workspace-core']
 extra_traits = []