diff --git a/Cargo.toml b/Cargo.toml
index 70fd6c5..e29c517 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -11,5 +11,9 @@ edition = "2018"
 [lib]
 name = "syscall"
 
+[features]
+rustc-dep-of-std = ["core", "bitflags/rustc-dep-of-std"]
+
 [dependencies]
 bitflags = "1.1.0"
+core = { version = "1.0.0", optional = true, package = "rustc-std-workspace-core" }