diff --git a/src/components/script/dom/bindings/codegen/CodegenRust.py b/src/components/script/dom/bindings/codegen/CodegenRust.py
index 9df2e31649a..befa1c3be90 100644
--- a/src/components/script/dom/bindings/codegen/CodegenRust.py
+++ b/src/components/script/dom/bindings/codegen/CodegenRust.py
@@ -702,13 +702,6 @@ def getJSToNativeConversionTemplate(type, descriptorProvider, failureCode=None,
 
             return handleDefault(conversionCode, default)
 
-        if isMember:
-            # We have to make a copy, because our jsval may well not
-            # live as long as our string needs to.
-            declType = CGGeneric("DOMString")
-            return ("%s\n" % getConversionCode(),
-                    declType, None, isOptional, None)
-
         declType = "DOMString"
         initialValue = None
         if type.nullable():
diff --git a/src/components/script/dom/webidls/TestBinding.webidl b/src/components/script/dom/webidls/TestBinding.webidl
index 56f54bb461b..c0be2eaacd2 100644
--- a/src/components/script/dom/webidls/TestBinding.webidl
+++ b/src/components/script/dom/webidls/TestBinding.webidl
@@ -4,6 +4,54 @@
 
 enum TestEnum { "", "foo", "bar" };
 
+/* dictionary TestDictionary {
+  // boolean booleanValue;
+  // byte byteValue;
+  // octet octetValue;
+  // short shortValue;
+  // unsigned short unsignedShortValue;
+  // long longValue;
+  // unsigned long unsignedLongValue;
+  // long long longLongValue;
+  // unsigned long long unsignedLongLongValue;
+  // float floatValue;
+  // double doubleValue;
+  // DOMString stringValue;
+  // TestEnum enumValue;
+  // Blob interfaceValue;
+  // any anyValue;
+}; */
+
+dictionary TestDictionaryDefaults {
+  // boolean booleanValue = false;
+  // byte byteValue = 7;
+  // octet octetValue = 7;
+  short shortValue = 7;
+  unsigned short unsignedShortValue = 7;
+  long longValue = 7;
+  unsigned long unsignedLongValue = 7;
+  // long long longLongValue = 7;
+  // unsigned long long unsignedLongLongValue = 7;
+  // float floatValue = 7.0;
+  // double doubleValue = 7.0;
+  DOMString stringValue = "";
+  // TestEnum enumValue = "bar";
+
+  // boolean? nullableBooleanValue = false;
+  // byte? nullableByteValue = 7;
+  // octet? nullableOctetValue = 7;
+  short? nullableShortValue = 7;
+  unsigned short? nullableUnsignedShortValue = 7;
+  long? nullableLongValue = 7;
+  unsigned long? nullableUnsignedLongValue = 7;
+  // long long? nullableLongLongValue = 7;
+  // unsigned long long? nullableUnsignedLongLongValue = 7;
+  // float? nullableFloatValue = 7.0;
+  // double? nullableDoubleValue = 7.0;
+  DOMString? nullableStringValue = "";
+  // TestEnum? nullableEnumValue = "bar";
+};
+
 interface TestBinding {
            attribute boolean booleanAttribute;
            attribute byte byteAttribute;