diff --git a/crates/webidl-tests/dictionary.js b/crates/webidl-tests/dictionary.js
index 46b2127a..7eadc871 100644
--- a/crates/webidl-tests/dictionary.js
+++ b/crates/webidl-tests/dictionary.js
@@ -20,3 +20,7 @@ global.assert_dict_required = function(c) {
   assert.strictEqual(c.b, "a");
   assert.strictEqual(c.c, 4);
 };
+
+global.assert_camel_case = function(dict) {
+  assert.strictEqual(dict.wierd_fieldName, 1);
+}
diff --git a/crates/webidl-tests/dictionary.rs b/crates/webidl-tests/dictionary.rs
index d769b9e9..21f86cda 100644
--- a/crates/webidl-tests/dictionary.rs
+++ b/crates/webidl-tests/dictionary.rs
@@ -16,6 +16,7 @@ extern "C" {
     #[wasm_bindgen(js_name = mk_dict_a)]
     fn mk_dict_a2() -> Option<A>;
     fn assert_dict_required(r: &Required);
+    fn assert_camel_case(dict: &PreserveNames);
 }
 
 #[wasm_bindgen_test]
@@ -51,3 +52,8 @@ fn many_types() {
 fn required() {
     assert_dict_required(Required::new(3, "a").c(4));
 }
+
+#[wasm_bindgen_test]
+fn correct_casing_in_js() {
+    assert_camel_case(PreserveNames::new().wierd_field_name(4));
+}
diff --git a/crates/webidl-tests/dictionary.webidl b/crates/webidl-tests/dictionary.webidl
index 75944104..f513323a 100644
--- a/crates/webidl-tests/dictionary.webidl
+++ b/crates/webidl-tests/dictionary.webidl
@@ -45,3 +45,7 @@ dictionary Required {
   required long a;
   long c;
 };
+
+dictionary PreserveNames {
+  long wierd_fieldName;
+};