diff --git a/librubyfmt/build.rs b/librubyfmt/build.rs
index 1e4efec0..ef94c098 100644
--- a/librubyfmt/build.rs
+++ b/librubyfmt/build.rs
@@ -52,6 +52,7 @@ fn main() -> Output {
         .file("src/rubyfmt.c")
         .object(ruby_checkout_path.join(&ripper))
         .include(ruby_checkout_path.join("include"))
+        .include(ruby_checkout_path.join(".ext/include/arm64-darwin20"))
         .include(ruby_checkout_path.join(".ext/include/arm64-darwin21"))
         .include(ruby_checkout_path.join(".ext/include/arm64-darwin22"))
         .include(ruby_checkout_path.join(".ext/include/x86_64-darwin21"))