diff --git a/packages/test/CMakeLists.txt b/packages/test/CMakeLists.txt
index 0c900593..1f55be23 100644
--- a/packages/test/CMakeLists.txt
+++ b/packages/test/CMakeLists.txt
@@ -253,6 +253,7 @@ add_test("tsfn2_st" "./tsfn2/binding.c" OFF)
 
 if((NOT IS_WASM) OR IS_EMSCRIPTEN OR IS_WASI_THREADS)
   add_test("string_mt" "./string/binding.c;./string/test_null.c" ON)
+  target_compile_definitions("string_mt" PRIVATE "NAPI_EXPERIMENTAL")
   add_test("pool" "./pool/binding.c" ON)
   add_test("tsfn" "./tsfn/binding.c" ON)
   add_test("async_cleanup_hook" "./async_cleanup_hook/binding.c" ON)
@@ -267,6 +268,7 @@ add_test("fnfac" "./fnfac/binding.c" OFF)
 add_test("general" "./general/binding.c" OFF)
 add_test("filename" "./filename/binding.c" OFF)
 add_test("string" "./string/binding.c;./string/test_null.c" OFF)
+target_compile_definitions("string" PRIVATE "NAPI_EXPERIMENTAL")
 add_test("property" "./property/binding.c" OFF)
 add_test("promise" "./promise/binding.c" OFF)
 add_test("object" "./object/test_null.c;./object/test_object.c" OFF)
diff --git a/packages/test/string/binding.c b/packages/test/string/binding.c
index 31425e2a..95108c98 100644
--- a/packages/test/string/binding.c
+++ b/packages/test/string/binding.c
@@ -1,3 +1,4 @@
+#include <js_native_api.h>
 #include <limits.h>  // INT_MAX
 
 #if !defined(__wasm__) || (defined(__EMSCRIPTEN__) || defined(__wasi__))
@@ -25,8 +26,6 @@ size_t strlen(const char *s)
 }
 #endif
 
-#define NAPI_EXPERIMENTAL
-#include <js_native_api.h>
 #include "../common.h"
 #include "../entry_point.h"
 #include "test_null.h"