diff --git a/tests/rustflags.rs b/tests/rustflags.rs
new file mode 100644
index 0000000..a3ac786
--- /dev/null
+++ b/tests/rustflags.rs
@@ -0,0 +1,11 @@
+extern crate autocfg;
+
+/// Tests that autocfg uses the RUSTFLAGS environment variable when running
+/// rustc.
+#[test]
+fn test_with_sysroot() {
+    std::env::set_var("RUSTFLAGS", "-L target/debug/deps");
+    std::env::set_var("OUT_DIR", "target");
+    let ac = autocfg::AutoCfg::new().unwrap();
+    assert!(ac.probe_sysroot_crate("autocfg"));
+}
\ No newline at end of file