diff --git a/rust-toolchain.toml b/rust-toolchain.toml
deleted file mode 100644
index 7f43b88..0000000
--- a/rust-toolchain.toml
+++ /dev/null
@@ -1,3 +0,0 @@
-[toolchain]
-channel = "nightly-2025-05-14"
-profile = "default"
diff --git a/src/aarch64.rs b/src/aarch64.rs
index 5caf773..3726d9b 100644
--- a/src/aarch64.rs
+++ b/src/aarch64.rs
@@ -22,8 +22,8 @@ pub fn encode_str<S: AsRef<str>>(input: S) -> String {
         while i + CHUNK <= n {
             let ptr = b.as_ptr().add(i);
 
-            /* ---- L1 prefetch: one cache line ahead ---- */
-            core::arch::asm!("prfm pldl1keep, [{0}, #128]", in(reg) ptr);
+            /* ---- L1 prefetch: CHUNK size ahead ---- */
+            core::arch::asm!("prfm pldl1keep, [{0}, #64]", in(reg) ptr);
             /* ------------------------------------------ */
 
             // load 64 B (four q-regs)