diff --git a/test/built-ins/RegExp/named-groups/groups-object.js b/test/built-ins/RegExp/named-groups/groups-object.js
new file mode 100644
index 0000000000000000000000000000000000000000..a7d2b5433ccb991f36de43a8042cd5b893b0ed27
--- /dev/null
+++ b/test/built-ins/RegExp/named-groups/groups-object.js
@@ -0,0 +1,34 @@
+// Copyright 2017 Aleksey Shvayka. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+description: Properties of the groups object are created with CreateDataProperty
+includes: [propertyHelper.js]
+esid: sec-regexpbuiltinexec
+features: [regexp-named-groups]
+info: >
+  Runtime Semantics: RegExpBuiltinExec ( R, S )
+    24. If R contains any GroupName,
+      a. Let groups be ObjectCreate(null).
+      b. Perform ! CreateDataProperty(A, "groups", groups).
+---*/
+
+// groups is created with Define, not Set
+let counter = 0;
+Object.defineProperty(Array.prototype, "groups", {set() { counter++; }});
+let match = /(?<x>.)/.exec("a");
+assert.sameValue(counter, 0);
+
+// groups is writable, enumerable and configurable
+// (from CreateDataProperty)
+verifyProperty(match, "groups", {
+  writable: true,
+  enumerable: true,
+  configurable: true,
+});
+
+// The '__proto__' property on the groups object is not special,
+// and does not affect the [[Prototype]] of the resulting groups object.
+let {groups} = /(?<__proto__>.)/.exec("a");
+assert.sameValue("a", groups.__proto__);
+assert.sameValue(null, Object.getPrototypeOf(groups));
diff --git a/test/built-ins/RegExp/named-groups/groups-properties.js b/test/built-ins/RegExp/named-groups/groups-properties.js
index 6d7b46ec63549a88e0264bb57a6c69cb91994415..8cf12152ce42bbf3238c3ffa50a701d86f25bfad 100644
--- a/test/built-ins/RegExp/named-groups/groups-properties.js
+++ b/test/built-ins/RegExp/named-groups/groups-properties.js
@@ -31,9 +31,3 @@ assert.sameValue(counter, 0);
 verifyWritable(groups, "x");
 verifyEnumerable(groups, "x");
 verifyConfigurable(groups, "x");
-
-// The '__proto__' property on the groups object is not special,
-// and does not affect the [[Prototype]] of the resulting groups object.
-groups = /(?<__proto__>a)/u.exec("a").groups;
-assert.sameValue("a", groups.__proto__);
-assert.sameValue(null, Object.getPrototypeOf(groups));
diff --git a/test/built-ins/RegExp/named-groups/non-unicode-malformed.js b/test/built-ins/RegExp/named-groups/non-unicode-malformed.js
index 993ff176167817aa414ebc046cec168693eaf20a..74d319a6a2d2ccf0cba6a8dbc7f1d8779290e071 100644
--- a/test/built-ins/RegExp/named-groups/non-unicode-malformed.js
+++ b/test/built-ins/RegExp/named-groups/non-unicode-malformed.js
@@ -23,6 +23,7 @@ assert(/\k<a/.test("k<a"));
 assert(/\k/.test("k"));
 assert.throws(SyntaxError, () => eval("/(?<a>.)\\k/"));
 assert.throws(SyntaxError, () => eval("/(?<a>.)\\k<a/"));
+assert.throws(SyntaxError, () => eval("/(?<a>.)\\k<>/"));
 assert.throws(SyntaxError, () => eval("/(?<a>.)\\k<b>/"));
 assert.throws(SyntaxError, () => eval("/(?<a>a)\\k<ab>/"));
 assert.throws(SyntaxError, () => eval("/(?<ab>a)\\k<a>/"));
diff --git a/test/built-ins/RegExp/named-groups/string-replace-escaped.js b/test/built-ins/RegExp/named-groups/string-replace-escaped.js
new file mode 100644
index 0000000000000000000000000000000000000000..7c6d405a23a5c5dc8d9b8e9505d1d5aae88ce0ca
--- /dev/null
+++ b/test/built-ins/RegExp/named-groups/string-replace-escaped.js
@@ -0,0 +1,24 @@
+// Copyright 2017 Aleksey Shvayka. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+description: Do not replace $<> preceded with $
+esid: sec-getsubstitution
+features: [regexp-named-groups]
+info: >
+  Runtime Semantics: GetSubstitution( matched, str, position, captures, namedCaptures, replacement )
+
+  12. These $ replacements are done left-to-right, and, once such a replacement is performed,
+  the new replacement text is not subject to further replacements.
+
+  Table: Replacement Text Symbol Substitutions
+
+  Unicode Characters: $$
+  Replacement text: $
+---*/
+
+let source = "(?<fst>.)";
+for (let flags of ["", "u"]) {
+  let re = new RegExp(source, flags);
+  assert.sameValue("$<fst>bc", "abc".replace(re, "$$<fst>"));
+}
diff --git a/test/built-ins/RegExp/named-groups/string-replace-unclosed.js b/test/built-ins/RegExp/named-groups/string-replace-unclosed.js
index 588bc3ed8571bbc250b325f490235e0d973a1220..1952b85050d36c2ebb3373e215f740fefb3ca1eb 100644
--- a/test/built-ins/RegExp/named-groups/string-replace-unclosed.js
+++ b/test/built-ins/RegExp/named-groups/string-replace-unclosed.js
@@ -21,4 +21,6 @@ for (let flags of ["", "u", "g", "gu"]) {
   let re = new RegExp(source, flags);
   assert.throws(SyntaxError, () => "abcd".replace(re, "$<snd"),
                 "unclosed named group in replacement should throw a SyntaxError");
+  assert.throws(SyntaxError, () => "abcd".replace(re, "$<>"),
+                "empty named group in replacement should throw a SyntaxError");
 }
diff --git a/test/built-ins/RegExp/named-groups/unicode-malformed.js b/test/built-ins/RegExp/named-groups/unicode-malformed.js
index 33a09a2689d7475f32195567c65beddf21fe2564..5c9c131a4857aec2ff24b9f1d580b4d218c87cdb 100644
--- a/test/built-ins/RegExp/named-groups/unicode-malformed.js
+++ b/test/built-ins/RegExp/named-groups/unicode-malformed.js
@@ -16,9 +16,11 @@ assert.throws(SyntaxError, () => eval("/(?<a>a)(?<a>a)/u"), "Duplicate name");
 assert.throws(SyntaxError, () => eval("/(?<a>a)(?<b>b)(?<a>a)/u"), "Duplicate name");
 assert.throws(SyntaxError, () => eval("/\\k<a>/u"), "Invalid reference");
 assert.throws(SyntaxError, () => eval("/\\k<a/u"), "Unterminated reference");
+assert.throws(SyntaxError, () => eval("/\\k<>/u"), "Empty reference");
 assert.throws(SyntaxError, () => eval("/\\k/u"), "Lone \k");
 assert.throws(SyntaxError, () => eval("/(?<a>.)\\k/u"), "Lone \k");
 assert.throws(SyntaxError, () => eval("/(?<a>.)\\k<a/u"), "Unterminated reference");
+assert.throws(SyntaxError, () => eval("/(?<a>.)\\k<>/u"), "Empty reference");
 assert.throws(SyntaxError, () => eval("/(?<a>.)\\k<b>/u"), "Invalid reference");
 assert.throws(SyntaxError, () => eval("/(?<a>a)\\k<ab>/u"), "Invalid reference");
 assert.throws(SyntaxError, () => eval("/(?<ab>a)\\k<a>/u"), "Invalid reference");