diff --git a/embassy-extras/build.rs b/embassy-extras/build.rs
new file mode 100644
index 00000000..e3388da2
--- /dev/null
+++ b/embassy-extras/build.rs
@@ -0,0 +1,11 @@
+use std::env;
+
+fn main() {
+    let target = env::var("TARGET").unwrap();
+
+    if target.starts_with("thumbv6m-") {
+        println!("cargo:rustc-cfg=armv6m");
+    } else if target.starts_with("thumbv8m.") {
+        println!("cargo:rustc-cfg=armv8m");
+    }
+}