diff --git a/aws-lc-sys/builder/cmake_builder.rs b/aws-lc-sys/builder/cmake_builder.rs
index 0f04d0b88a..b10e20cf9d 100644
--- a/aws-lc-sys/builder/cmake_builder.rs
+++ b/aws-lc-sys/builder/cmake_builder.rs
@@ -169,7 +169,8 @@ impl CmakeBuilder {
 
         // Only needed when cross-compiling
         if target_underscored() == "aarch64_pc_windows_msvc" {
-            cmake_cfg.generator("Ninja");
+            // https://stackoverflow.com/questions/64189111/how-to-use-clang-cl-llvm-with-vs2019-cmake
+            cmake_cfg.define("CMAKE_GENERATOR_TOOLSET", "ClangCL");
             cmake_cfg.define("CMAKE_ASM_COMPILER_TARGET", "arm64-pc-windows-msvc");
             cmake_cfg.define("CMAKE_ASM_COMPILER", "clang-cl");
         }