diff --git a/build_release.sh b/build_release.sh
index 333919f..f7434bc 100755
--- a/build_release.sh
+++ b/build_release.sh
@@ -1,11 +1,12 @@
 #!/bin/sh
 
-# Set rustflags as empty to build for legacy hosts.
+# Set rustflags without target-cpu to build for legacy hosts.
 # I only build this for windows because Linux users on old machines can just compile their own binary
-RUSTFLAGS="" cargo build --release --target=x86_64-pc-windows-gnu --locked
+# --emit=asm forces rustc to compile the crate with only one thread, which can help the optimizer (1-2% faster on my machine)
+RUSTFLAGS="--emit asm" cargo build --release --target=x86_64-pc-windows-gnu --locked
 mv target/x86_64-pc-windows-gnu/release/adaptivegrain_rs.dll ./adaptivegrain_rs-no-fma.dll
-RUSTFLAGS="-C target-cpu=haswell" cargo build --release --locked
-RUSTFLAGS="-C target-cpu=haswell" cargo build --release --target=x86_64-pc-windows-gnu --locked
+RUSTFLAGS="-C target-cpu=haswell --emit asm" cargo build --release --locked
+RUSTFLAGS="-C target-cpu=haswell --emit asm" cargo build --release --target=x86_64-pc-windows-gnu --locked
 mv target/x86_64-pc-windows-gnu/release/adaptivegrain_rs.dll ./
 mv target/release/libadaptivegrain_rs.so ./
 strip libadaptivegrain_rs.so