diff --git a/consensus/src/bin/scan_chain.rs b/consensus/src/bin/scan_chain.rs
index ed8933b5..95f0df05 100644
--- a/consensus/src/bin/scan_chain.rs
+++ b/consensus/src/bin/scan_chain.rs
@@ -36,7 +36,7 @@ use monero_consensus::{blocks::randomx_seed_height, HardFork};
 
 mod tx_pool;
 
-const MAX_BLOCKS_IN_RANGE: u64 = 1000;
+const MAX_BLOCKS_IN_RANGE: u64 = 500;
 const BATCHES_IN_REQUEST: u64 = 3;
 const MAX_BLOCKS_HEADERS_IN_RANGE: u64 = 1000;
 
@@ -226,7 +226,8 @@ where
 
     tokio::spawn(async move {
         while let Some(blocks) = incoming_blocks.next().await {
-            if blocks.last().unwrap().header.major_version >= 12 {
+            // RX technically starts at hf 12 but we do 11 so the seed hash is in the cache.
+            if blocks.last().unwrap().header.major_version >= 11 {
                 let unwrapped_rx_vms = randomx_vms.as_mut().unwrap();
 
                 let blocks = rayon_spawn_async(move || {
diff --git a/cryptonight/build.rs b/cryptonight/build.rs
index 6551aa8b..bace0d82 100644
--- a/cryptonight/build.rs
+++ b/cryptonight/build.rs
@@ -21,13 +21,14 @@ fn main() {
         .file("c/skein.c")
         .file("c/slow-hash.c")
         .file("c/CryptonightR_JIT.c")
-        .file("c/CryptonightR_template.S")
         .flag("-O3")
         .flag("-fexceptions");
 
     let target = env::var("TARGET").unwrap();
     if target.contains("x86_64") {
-        cfg.flag("-maes").flag("-msse2");
+        cfg.file("c/CryptonightR_template.S")
+            .flag("-maes")
+            .flag("-msse2");
     }
 
     cfg.compile("cryptonight")