diff --git a/storage/src/mozStorageStatementParams.cpp b/storage/src/mozStorageStatementParams.cpp
index 8bf8258a8dfd..e87f2f47f713 100644
--- a/storage/src/mozStorageStatementParams.cpp
+++ b/storage/src/mozStorageStatementParams.cpp
@@ -80,6 +80,7 @@ mozStorageStatementParams::GetScriptableFlags(PRUint32 *aScriptableFlags)
 {
     *aScriptableFlags =
         nsIXPCScriptable::WANT_SETPROPERTY |
+        nsIXPCScriptable::WANT_NEWENUMERATE |
         nsIXPCScriptable::WANT_NEWRESOLVE |
         nsIXPCScriptable::ALLOW_PROP_MODS_DURING_RESOLVE;
     return NS_OK;
@@ -180,7 +181,62 @@ NS_IMETHODIMP
 mozStorageStatementParams::NewEnumerate(nsIXPConnectWrappedNative *wrapper, JSContext * cx,
                                      JSObject * obj, PRUint32 enum_op, jsval * statep, jsid *idp, PRBool *_retval)
 {
-    return NS_ERROR_NOT_IMPLEMENTED;
+    NS_ENSURE_TRUE(mStatement, NS_ERROR_NOT_INITIALIZED);
+
+    switch (enum_op) {
+        case JSENUMERATE_INIT:
+        {
+            // Start our internal index at zero.
+            *statep = JSVAL_ZERO;
+
+            // And set our length, if needed.
+            if (idp)
+                *idp = INT_TO_JSVAL(mParamCount);
+
+            break;
+        }
+        case JSENUMERATE_NEXT:
+        {
+            NS_ASSERTION(*statep != JSVAL_NULL, "Internal state is null!");
+
+            // Make sure we are in range first.
+            PRUint32 index = static_cast<PRUint32>(JSVAL_TO_INT(*statep));
+            if (index >= mParamCount) {
+                *statep = JSVAL_NULL;
+                return NS_OK;
+            }
+
+            // Get the name of our parameter.
+            nsCAutoString name;
+            nsresult rv = mStatement->GetParameterName(index, name);
+            NS_ENSURE_SUCCESS(rv, rv);
+
+            // But drop the first character, which is going to be a ':'.
+            JSString *jsname = JS_NewStringCopyN(cx, &(name.get()[1]),
+                                                 name.Length() - 1);
+            NS_ENSURE_TRUE(jsname, NS_ERROR_OUT_OF_MEMORY);
+
+            // Set our name.
+            if (!JS_ValueToId(cx, STRING_TO_JSVAL(jsname), idp)) {
+                *_retval = PR_FALSE;
+                return NS_OK;
+            }
+
+            // And increment our index.
+            *statep = INT_TO_JSVAL(++index);
+
+            break;
+        }
+        case JSENUMERATE_DESTROY:
+        {
+            // Clear our state.
+            *statep = JSVAL_NULL;
+
+            break;
+        }
+    }
+
+    return NS_OK;
 }
 
 /* PRBool newResolve (in nsIXPConnectWrappedNative wrapper, in JSContextPtr cx, in JSObjectPtr obj, in JSVal id, in PRUint32 flags, out JSObjectPtr objp); */
@@ -189,11 +245,18 @@ mozStorageStatementParams::NewResolve(nsIXPConnectWrappedNative *wrapper, JSCont
                                    JSObject * obj, jsval id, PRUint32 flags, JSObject * *objp, PRBool *_retval)
 {
     NS_ENSURE_TRUE(mStatement, NS_ERROR_NOT_INITIALIZED);
+    // We do not throw at any point after this unless our index is out of range
+    // because we want to allow the prototype chain to be checked for the
+    // property.
 
     PRUint32 idx;
 
     if (JSVAL_IS_INT(id)) {
         idx = JSVAL_TO_INT(id);
+
+        // Ensure that our index is within range.
+        if (idx >= mParamCount)
+            return NS_ERROR_INVALID_ARG;
     }
     else if (JSVAL_IS_STRING(id)) {
         JSString *str = JSVAL_TO_STRING(id);
@@ -203,23 +266,21 @@ mozStorageStatementParams::NewResolve(nsIXPConnectWrappedNative *wrapper, JSCont
         nsCAutoString name(":");
         name.Append(NS_ConvertUTF16toUTF8(nameChars, nameLength));
 
-        // check to see if there's a parameter with this name
+        // Check to see if there's a parameter with this name, and if not, let
+        // the rest of the prototype chain be checked.
         nsresult rv = mStatement->GetParameterIndex(name, &idx);
-        NS_ENSURE_SUCCESS(rv, rv);
+        if (NS_FAILED(rv))
+            return NS_OK;
 
-        PRBool success = JS_DefineUCProperty(cx, obj, nameChars, nameLength,
-                                             JSVAL_VOID, nsnull, nsnull, 0);
-        NS_ENSURE_TRUE(success, NS_ERROR_FAILURE);
+        *_retval = JS_DefineUCProperty(cx, obj, nameChars, nameLength,
+                                       JSVAL_VOID, nsnull, nsnull, 0);
+        NS_ENSURE_TRUE(*_retval, NS_OK);
     }
     else {
         // We do not handle other types.
-        return NS_ERROR_UNEXPECTED;
+        return NS_OK;
     }
 
-    // Ensure that our index is within range.
-    if (idx >= mParamCount)
-        return NS_ERROR_INVALID_ARG;
-
     *_retval = ::JS_DefineElement(cx, obj, idx, JSVAL_VOID, nsnull, nsnull, 0);
     if (*_retval)
         *objp = obj;
diff --git a/storage/test/unit/test_js_helpers_enumerate.js b/storage/test/unit/test_js_helpers_enumerate.js
new file mode 100644
index 000000000000..88664d5eade7
--- /dev/null
+++ b/storage/test/unit/test_js_helpers_enumerate.js
@@ -0,0 +1,81 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: sw=2 ts=2 sts=2 et
+ * ***** BEGIN LICENSE BLOCK *****
+ * Version: MPL 1.1/GPL 2.0/LGPL 2.1
+ *
+ * The contents of this file are subject to the Mozilla Public License Version
+ * 1.1 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ * http://www.mozilla.org/MPL/
+ *
+ * Software distributed under the License is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
+ * for the specific language governing rights and limitations under the
+ * License.
+ *
+ * The Original Code is Storage Test Code.
+ *
+ * The Initial Developer of the Original Code is
+ * Mozilla Corporation.
+ * Portions created by the Initial Developer are Copyright (C) 2009
+ * the Initial Developer. All Rights Reserved.
+ *
+ * Contributor(s):
+ *   Shawn Wilsher <me@shawnwilsher.com> (Original Author)
+ *
+ * Alternatively, the contents of this file may be used under the terms of
+ * either the GNU General Public License Version 2 or later (the "GPL"), or
+ * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
+ * in which case the provisions of the GPL or the LGPL are applicable instead
+ * of those above. If you wish to allow use of your version of this file only
+ * under the terms of either the GPL or the LGPL, and not to allow others to
+ * use your version of this file under the terms of the MPL, indicate your
+ * decision by deleting the provisions above and replace them with the notice
+ * and other provisions required by the GPL or the LGPL. If you do not delete
+ * the provisions above, a recipient may use your version of this file under
+ * the terms of any one of the MPL, the GPL or the LGPL.
+ *
+ * ***** END LICENSE BLOCK ***** */
+
+/**
+ * This file tests that the JS language helpers have the ability to enumerate
+ * their properties.
+ */
+
+////////////////////////////////////////////////////////////////////////////////
+//// Test Functions
+
+function test_params_enumerate()
+{
+  let stmt = getOpenedDatabase().createStatement(
+    "SELECT * FROM test WHERE id IN (:a, :b, :c)"
+  );
+
+  // Make sure they are right.
+  let expected = ["a", "b", "c"];
+  let index = 0;
+  for (let name in stmt.params)
+    do_check_eq(name, expected[index++]);
+}
+
+
+////////////////////////////////////////////////////////////////////////////////
+//// Test Runner
+
+let tests = [
+  test_params_enumerate,
+];
+function run_test()
+{
+  cleanup();
+
+  // Create our database.
+  getOpenedDatabase().executeSimpleSQL(
+    "CREATE TABLE test (" +
+      "id INTEGER PRIMARY KEY " +
+    ")"
+  );
+
+  // Run the tests.
+  tests.forEach(function(test) test());
+}