diff --git a/CHANGELOG.asciidoc b/CHANGELOG.asciidoc
index b88d717..c7a2b36 100644
--- a/CHANGELOG.asciidoc
+++ b/CHANGELOG.asciidoc
@@ -25,7 +25,8 @@
 
 This release also includes changes from <<release-3-4-3, 3.4.3>>.
 
-* Allowed the possibility for the user of `null` in Gremlin.
+* Allowed the possibility for the propagation of `null` as a `Traverser` in Gremlin.
+* Ensured better consistency of the use of `null` as arguments to mutation steps.
 * Added a `Graph.Feature` for `supportsNullPropertyValues`.
 * Refactored `MapStep` to move its logic to `ScalarMapStep` so that the old behavior could be preserved while allow other implementations to have more flexibility.
 * Modified TinkerGraph to support `null` property values and can be configured to disable that feature.
diff --git a/gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/process/traversal/dsl/graph/GraphTraversalSource.java b/gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/process/traversal/dsl/graph/GraphTraversalSource.java
index 0b2398f..011bae7 100644
--- a/gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/process/traversal/dsl/graph/GraphTraversalSource.java
+++ b/gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/process/traversal/dsl/graph/GraphTraversalSource.java
@@ -297,7 +297,8 @@
 
 
     /**
-     * Spawns a {@link GraphTraversal} by adding a vertex with the specified label.
+     * Spawns a {@link GraphTraversal} by adding a vertex with the specified label. If the {@code label} is
+     * {@code null} then it will default to {@link Vertex#DEFAULT_LABEL}.
      */
     public GraphTraversal<Vertex, Vertex> addV(final String label) {
         final GraphTraversalSource clone = this.clone();
@@ -307,7 +308,8 @@
     }
 
     /**
-     * Spawns a {@link GraphTraversal} by adding a vertex with the label as determined by a {@link Traversal}.
+     * Spawns a {@link GraphTraversal} by adding a vertex with the label as determined by a {@link Traversal}. If the
+     * {@code vertexLabelTraversal} is {@code null} then it will default to {@link Vertex#DEFAULT_LABEL}.
      */
     public GraphTraversal<Vertex, Vertex> addV(final Traversal<?, String> vertexLabelTraversal) {
         final GraphTraversalSource clone = this.clone();
diff --git a/gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/process/traversal/step/map/AddVertexStartStep.java b/gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/process/traversal/step/map/AddVertexStartStep.java
index 547517c..6273fa2 100644
--- a/gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/process/traversal/step/map/AddVertexStartStep.java
+++ b/gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/process/traversal/step/map/AddVertexStartStep.java
@@ -58,7 +58,7 @@
 
     public AddVertexStartStep(final Traversal.Admin traversal, final Traversal<?, String> vertexLabelTraversal) {
         super(traversal);
-        this.parameters.set(this, T.label, vertexLabelTraversal);
+        this.parameters.set(this, T.label, null == vertexLabelTraversal ? Vertex.DEFAULT_LABEL : vertexLabelTraversal);
     }
 
     @Override
diff --git a/gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/process/traversal/step/map/AddVertexStep.java b/gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/process/traversal/step/map/AddVertexStep.java
index 296e8b5..b963db2 100644
--- a/gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/process/traversal/step/map/AddVertexStep.java
+++ b/gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/process/traversal/step/map/AddVertexStep.java
@@ -53,7 +53,7 @@
 
     public AddVertexStep(final Traversal.Admin traversal, final Traversal.Admin<S,String> vertexLabelTraversal) {
         super(traversal);
-        this.parameters.set(this, T.label, vertexLabelTraversal);
+        this.parameters.set(this, T.label, null == vertexLabelTraversal ? Vertex.DEFAULT_LABEL : vertexLabelTraversal);
     }
 
     @Override
diff --git a/gremlin-core/src/test/java/org/apache/tinkerpop/gremlin/process/traversal/step/map/AddVertexStepTest.java b/gremlin-core/src/test/java/org/apache/tinkerpop/gremlin/process/traversal/step/map/AddVertexStepTest.java
new file mode 100644
index 0000000..7022bc8
--- /dev/null
+++ b/gremlin-core/src/test/java/org/apache/tinkerpop/gremlin/process/traversal/step/map/AddVertexStepTest.java
@@ -0,0 +1,48 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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 org.apache.tinkerpop.gremlin.process.traversal.step.map;
+
+import org.apache.tinkerpop.gremlin.process.traversal.Traversal;
+import org.apache.tinkerpop.gremlin.structure.T;
+import org.apache.tinkerpop.gremlin.structure.Vertex;
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+import static org.mockito.Mockito.mock;
+
+public class AddVertexStepTest {
+
+    @Test
+    public void shouldDefaultTheLabelIfNullString() {
+        final Traversal.Admin t = mock(Traversal.Admin.class);
+        final AddVertexStartStep starStep = new AddVertexStartStep(t, (String) null);
+        assertEquals(Vertex.DEFAULT_LABEL, starStep.getParameters().getRaw().get(T.label).get(0));
+        final AddVertexStep step = new AddVertexStep(t, (String) null);
+        assertEquals(Vertex.DEFAULT_LABEL, starStep.getParameters().getRaw().get(T.label).get(0));
+    }
+
+    @Test
+    public void shouldDefaultTheLabelIfNullTraversal() {
+        final Traversal.Admin t = mock(Traversal.Admin.class);
+        final AddVertexStartStep starStep = new AddVertexStartStep(t, (Traversal<?,String>) null);
+        assertEquals(Vertex.DEFAULT_LABEL, starStep.getParameters().getRaw().get(T.label).get(0));
+        final AddVertexStep step = new AddVertexStep(t, (String) null);
+        assertEquals(Vertex.DEFAULT_LABEL, starStep.getParameters().getRaw().get(T.label).get(0));
+    }
+}