diff --git a/Cargo.toml b/Cargo.toml
index 226d416..a5aab9e 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -32,3 +32,4 @@ i128 = []
 
 [build-dependencies]
 autocfg = "1"
+tempfile = "3"
diff --git a/build.rs b/build.rs
index 98b06be..b3e2958 100644
--- a/build.rs
+++ b/build.rs
@@ -1,5 +1,6 @@
 fn main() {
-    let ac = autocfg::new();
+    let temp_dir = tempfile::tempdir().expect("failed to create temp dir");
+    let ac = autocfg::AutoCfg::with_dir(temp_dir.path()).unwrap();
 
     ac.emit_expression_cfg("1f64.total_cmp(&2f64)", "has_total_cmp"); // 1.62