diff --git a/src/main/java/ch/digitalfondue/jfiveparse/AttributeNode.java b/src/main/java/ch/digitalfondue/jfiveparse/AttributeNode.java
index 5139cfd8..c3d2476a 100644
--- a/src/main/java/ch/digitalfondue/jfiveparse/AttributeNode.java
+++ b/src/main/java/ch/digitalfondue/jfiveparse/AttributeNode.java
@@ -99,7 +99,7 @@ public boolean equals(Object obj) {
 
         if (obj instanceof AttributeNode other) {
             return name.equals(other.name) && //
-                    getValue().equals(other.getValue()) && //
+                    Objects.equals(getValue(), other.getValue()) && //
                     Objects.equals(prefix, other.prefix) && //
                     Objects.equals(namespace, other.namespace);
         }
diff --git a/src/main/java/ch/digitalfondue/jfiveparse/DOMTokenList.java b/src/main/java/ch/digitalfondue/jfiveparse/DOMTokenList.java
index a847b457..59f09549 100644
--- a/src/main/java/ch/digitalfondue/jfiveparse/DOMTokenList.java
+++ b/src/main/java/ch/digitalfondue/jfiveparse/DOMTokenList.java
@@ -105,7 +105,13 @@ public boolean toggle(String name) {
     }
 
     public boolean toggle(String name, boolean condition) {
-        return condition && toggle(name);
+        if (condition) {
+            add(name);
+            return true;
+        } else {
+            remove(name);
+            return false;
+        }
     }
 
     public String item(int index) {
diff --git a/src/main/java/ch/digitalfondue/jfiveparse/Document.java b/src/main/java/ch/digitalfondue/jfiveparse/Document.java
index ca39483b..a8087a51 100644
--- a/src/main/java/ch/digitalfondue/jfiveparse/Document.java
+++ b/src/main/java/ch/digitalfondue/jfiveparse/Document.java
@@ -109,7 +109,7 @@ public Node cloneNode(boolean deep) {
         Document cloned = new Document();
         if (doctype != null) {
             cloned.doctype = (DocumentType) doctype.cloneNode(true);
-            cloned.doctype.parentNode = this;
+            cloned.doctype.parentNode = cloned;
         }
         if (!deep) {
             return cloned;
diff --git a/src/test/java/ch/digitalfondue/jfiveparse/AttributeNodeTest.java b/src/test/java/ch/digitalfondue/jfiveparse/AttributeNodeTest.java
new file mode 100644
index 00000000..6f9d73c4
--- /dev/null
+++ b/src/test/java/ch/digitalfondue/jfiveparse/AttributeNodeTest.java
@@ -0,0 +1,42 @@
+/**
+ * Copyright © 2015 digitalfondue (info@digitalfondue.ch)
+ *
+ * Licensed under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package ch.digitalfondue.jfiveparse;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+/**
+ * Tests for {@link AttributeNode}.
+ */
+class AttributeNodeTest {
+
+    @Test
+    void equalsWithBothValuesNull() {
+        AttributeNode a = new AttributeNode("src", null);
+        AttributeNode b = new AttributeNode("src", null);
+        assertEquals(a, b);
+        assertEquals(b, a);
+    }
+
+    @Test
+    void equalsWithOneValueNull() {
+        AttributeNode a = new AttributeNode("src", null);
+        AttributeNode b = new AttributeNode("src", "image.png");
+        assertNotEquals(a, b);
+        assertNotEquals(b, a);
+    }
+}
diff --git a/src/test/java/ch/digitalfondue/jfiveparse/DOMTokenListTest.java b/src/test/java/ch/digitalfondue/jfiveparse/DOMTokenListTest.java
new file mode 100644
index 00000000..1a58281e
--- /dev/null
+++ b/src/test/java/ch/digitalfondue/jfiveparse/DOMTokenListTest.java
@@ -0,0 +1,62 @@
+/**
+ * Copyright © 2015 digitalfondue (info@digitalfondue.ch)
+ *
+ * Licensed under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package ch.digitalfondue.jfiveparse;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+
+class DOMTokenListTest {
+
+    private DOMTokenList classListFor(String classAttr) {
+        Element el = new Element("div");
+        if (classAttr != null) {
+            el.setAttribute("class", classAttr);
+        }
+        return new DOMTokenList(el, "class");
+    }
+
+    @Test
+    void toggleWithForceTrueAddsAbsentToken() {
+        DOMTokenList list = classListFor(null);
+        assertTrue(list.toggle("foo", true));
+        assertTrue(list.contains("foo"));
+    }
+
+    @Test
+    void toggleWithForceTrueKeepsPresentToken() {
+        DOMTokenList list = classListFor("foo");
+        assertTrue(list.toggle("foo", true));
+        assertTrue(list.contains("foo"));
+    }
+
+    @Test
+    void toggleWithForceFalseRemovesPresentToken() {
+        DOMTokenList list = classListFor("foo bar");
+        assertFalse(list.toggle("foo", false));
+        assertFalse(list.contains("foo"));
+        assertTrue(list.contains("bar"));
+    }
+
+    @Test
+    void toggleWithForceFalseIsNoOpOnAbsentToken() {
+        DOMTokenList list = classListFor("bar");
+        assertFalse(list.toggle("foo", false));
+        assertFalse(list.contains("foo"));
+        assertTrue(list.contains("bar"));
+    }
+}
diff --git a/src/test/java/ch/digitalfondue/jfiveparse/DocumentTest.java b/src/test/java/ch/digitalfondue/jfiveparse/DocumentTest.java
index 02380549..e30d0e8f 100644
--- a/src/test/java/ch/digitalfondue/jfiveparse/DocumentTest.java
+++ b/src/test/java/ch/digitalfondue/jfiveparse/DocumentTest.java
@@ -19,7 +19,7 @@
 
 import java.io.StringReader;
 
-import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.*;
 
 
 class DocumentTest {
@@ -44,4 +44,38 @@ void checkDocumentRelatedMethods() {
 
         assertEquals("<body id=\"newBody\"></body>", d1.getBody().getOuterHTML());
     }
+
+    @Test
+    void cloneNodeShallowDoctypeParentIsClone() {
+        Document original = new Parser().parse("<!DOCTYPE html><div>Hello</div>");
+        Document cloned = (Document) original.cloneNode(false);
+
+        assertNotNull(cloned.getDoctype());
+        assertSame(cloned, cloned.getDoctype().getParentNode());
+        assertNotSame(original, cloned.getDoctype().getParentNode());
+    }
+
+    @Test
+    void cloneNodeDeepDoctypeParentIsClone() {
+        Document original = new Parser().parse("<!DOCTYPE html><div>Hello</div>");
+        Document cloned = (Document) original.cloneNode(true);
+
+        assertNotNull(cloned.getDoctype());
+        assertSame(cloned, cloned.getDoctype().getParentNode());
+        assertNotSame(original, cloned.getDoctype().getParentNode());
+    }
+
+    @Test
+    void cloneNodeDeepPreservesContent() {
+        Document original = new Parser().parse("<!DOCTYPE html><div>Hello</div>");
+        Document cloned = (Document) original.cloneNode(true);
+        assertEquals(HtmlSerializer.serialize(original), HtmlSerializer.serialize(cloned));
+    }
+
+    @Test
+    void cloneNodeShallowHasNoChildren() {
+        Document original = new Parser().parse("<!DOCTYPE html><div>Hello</div>");
+        Document cloned = (Document) original.cloneNode(false);
+        assertEquals(0, cloned.getChildNodes().size());
+    }
 }
diff --git a/src/test/java/ch/digitalfondue/jfiveparse/NodeTest.java b/src/test/java/ch/digitalfondue/jfiveparse/NodeTest.java
index b13c3c73..f1300943 100644
--- a/src/test/java/ch/digitalfondue/jfiveparse/NodeTest.java
+++ b/src/test/java/ch/digitalfondue/jfiveparse/NodeTest.java
@@ -157,9 +157,14 @@ void testClass() {
         assertEquals(Arrays.asList("hurr", "plop"), e.getClassList());
 
         assertFalse(e.getClassList().toggle("plop", false));
-        assertEquals(Arrays.asList("hurr", "plop"), e.getClassList());
-        assertFalse(e.getClassList().toggle("plop", true));
-        assertEquals(List.of("hurr"), e.getClassList());
+        assertEquals(Arrays.asList("hurr"), e.getClassList());
+        assertFalse(e.getClassList().toggle("plop", false));
+        assertEquals(Arrays.asList("hurr"), e.getClassList());
+
+        assertTrue(e.getClassList().toggle("plop", true));
+        assertEquals(List.of("hurr", "plop"), e.getClassList());
+        assertTrue(e.getClassList().toggle("plop", true));
+        assertEquals(List.of("hurr", "plop"), e.getClassList());
 
         Document doc2 = parser.parse("<div id=myid class=' my class    \n abc '></div>");
         Element e2 = doc2.getElementById("myid");