diff --git a/packages/gems/js/ext/js/js-core.c b/packages/gems/js/ext/js/js-core.c
index c28804f2e4..f81ecf1173 100644
--- a/packages/gems/js/ext/js/js-core.c
+++ b/packages/gems/js/ext/js/js-core.c
@@ -200,6 +200,11 @@ static VALUE _rb_js_obj_aref(VALUE obj, VALUE key) {
 static VALUE _rb_js_obj_aset(VALUE obj, VALUE key, VALUE val) {
   struct jsvalue *p = check_jsvalue(obj);
   VALUE rv = _rb_js_try_convert(rb_mJS, val);
+  if (rv == Qnil) {
+    rb_raise(rb_eTypeError,
+             "wrong argument type %s (expected JS::Object like object)",
+             rb_class2name(rb_obj_class(val)));
+  }
   struct jsvalue *v = check_jsvalue(rv);
   rb_js_abi_host_string_t key_abi_str;
   key = rb_obj_as_string(key);
diff --git a/packages/npm-packages/ruby-wasm-wasi/test/unit/test_object.rb b/packages/npm-packages/ruby-wasm-wasi/test/unit/test_object.rb
index b4a53929f7..5fb77c8e21 100644
--- a/packages/npm-packages/ruby-wasm-wasi/test/unit/test_object.rb
+++ b/packages/npm-packages/ruby-wasm-wasi/test/unit/test_object.rb
@@ -346,6 +346,12 @@ def test_member_set
     assert_equal 41.to_s, object["bar"].to_s
   end
 
+  def test_member_set_with_non_js_object
+    assert_raise_message("wrong argument type Object (expected JS::Object like object)") do
+      JS.global[:tmp] = Object.new
+    end
+  end
+
   def test_member_set_with_stress_gc
     GC.stress = true
     JS.global[:tmp] = "1"