diff --git a/cmake/wasi-sdk-sysroot.cmake b/cmake/wasi-sdk-sysroot.cmake
index 21c8c4f..2ef0591 100644
--- a/cmake/wasi-sdk-sysroot.cmake
+++ b/cmake/wasi-sdk-sysroot.cmake
@@ -106,10 +106,14 @@ add_custom_target(compiler-rt-post-build
   COMMAND ${CMAKE_COMMAND} -E copy_directory
     ${clang_resource_dir}/include ${wasi_resource_dir}/include
 
-  # Copy the `lib/wasi` folder to `libc/wasi{p1,p2}` to ensure that those
-  # OS-strings also work for looking up the compiler-rt.a file.
+  # Copy the `lib/wasi` folder to `libc/wasi{p1,p2}{-threads}?` to ensure that
+  # those OS-strings also work for looking up the compiler-rt.a file.
+  COMMAND ${CMAKE_COMMAND} -E copy_directory
+    ${wasi_resource_dir}/lib/wasi ${wasi_resource_dir}/lib/wasi-threads
   COMMAND ${CMAKE_COMMAND} -E copy_directory
     ${wasi_resource_dir}/lib/wasi ${wasi_resource_dir}/lib/wasip1
+  COMMAND ${CMAKE_COMMAND} -E copy_directory
+    ${wasi_resource_dir}/lib/wasi ${wasi_resource_dir}/lib/wasip1-threads
   COMMAND ${CMAKE_COMMAND} -E copy_directory
     ${wasi_resource_dir}/lib/wasi ${wasi_resource_dir}/lib/wasip2
 
diff --git a/tests/general/builtin-floatdidf.c b/tests/general/builtin-floatdidf.c
new file mode 100644
index 0000000..ddfd5c9
--- /dev/null
+++ b/tests/general/builtin-floatdidf.c
@@ -0,0 +1,10 @@
+// Primarily check that `libclang_rt.builtins-wasm32.a` functions are present
+// and work as expected on all tested targets, not the builtin functionality.
+
+#include <assert.h>
+
+int main() {
+  double f = __floatdidf(0);
+  assert(f == 0.0);
+  return 0;
+}