diff --git a/mountpoint-s3-crt-sys/build.rs b/mountpoint-s3-crt-sys/build.rs
index 8ed91fa69..adfd91046 100644
--- a/mountpoint-s3-crt-sys/build.rs
+++ b/mountpoint-s3-crt-sys/build.rs
@@ -243,6 +243,7 @@ fn compile_crt(output_dir: &Path) -> PathBuf {
         if lib.package_name == "aws-lc" {
             builder.define("DISABLE_PERL", "ON");
             builder.define("DISABLE_GO", "ON");
+            builder.define("BUILD_TOOL", "OFF");
         }
 
         // Force compiler optimizations for aws-checksums even in debug builds to improve throughput