diff --git a/src/lib.rs b/src/lib.rs
index fffca44..f6f7d0a 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -85,6 +85,11 @@ pub mod ext {
       out
    }
 
+   #[inline]
+   #[cfg(target_arch = "aarch64")]
+   pub unsafe fn __readfsdword(offset: u32) -> usize {
+      0usize
+   }
    #[inline]
    #[cfg(target_arch = "aarch64")]
    pub unsafe fn __readgsqword(offset: u32) -> usize {