diff --git a/pom.xml b/pom.xml
index 6ca2c78..51fff91 100644
--- a/pom.xml
+++ b/pom.xml
@@ -24,7 +24,7 @@
 	<properties>
 		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
 		<arangodb-java-driver.version>7.17.0</arangodb-java-driver.version>
-		<tinkerpop.version>3.3.11</tinkerpop.version>
+		<tinkerpop.version>3.7.3</tinkerpop.version>
 		<junit.version>4.13.1</junit.version>
 		<logback-classic.version>1.2.13</logback-classic.version>
 		<commons-lang3.version>3.4</commons-lang3.version>
diff --git a/src/main/java/com/arangodb/tinkerpop/gremlin/client/ArangoDBPropertyFilter.java b/src/main/java/com/arangodb/tinkerpop/gremlin/client/ArangoDBPropertyFilter.java
index ed205c1..64b07fe 100644
--- a/src/main/java/com/arangodb/tinkerpop/gremlin/client/ArangoDBPropertyFilter.java
+++ b/src/main/java/com/arangodb/tinkerpop/gremlin/client/ArangoDBPropertyFilter.java
@@ -13,7 +13,7 @@
 import java.util.List;
 import java.util.Map;
 
-import org.apache.commons.lang.StringUtils;
+import org.apache.commons.lang3.StringUtils;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
diff --git a/src/main/java/com/arangodb/tinkerpop/gremlin/structure/ArangoDBElementProperty.java b/src/main/java/com/arangodb/tinkerpop/gremlin/structure/ArangoDBElementProperty.java
index 829bef3..f9f36bb 100644
--- a/src/main/java/com/arangodb/tinkerpop/gremlin/structure/ArangoDBElementProperty.java
+++ b/src/main/java/com/arangodb/tinkerpop/gremlin/structure/ArangoDBElementProperty.java
@@ -10,6 +10,7 @@
 
 import java.util.NoSuchElementException;
 
+import com.fasterxml.jackson.annotation.JsonIgnore;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import org.apache.tinkerpop.gremlin.structure.Property;
 import org.apache.tinkerpop.gremlin.structure.util.ElementHelper;
@@ -90,7 +91,7 @@ public ArangoDBElementProperty(String key, String name, V value, ArangoDBBaseDoc
 	    super(key, label, owner.graph());
         this.name = name;
         this.value = value;
-        this.valueType = value.getClass().getCanonicalName();
+        this.valueType = (value != null ? value.getClass() : Void.class).getCanonicalName();
     }
 
     /**
@@ -106,6 +107,7 @@ public ArangoDBElementProperty(String name, V value, ArangoDBBaseDocument owner,
         this(null, name, value, owner, label);
     }
 
+    @JsonIgnore
 	@Override
 	public boolean isPresent() {
 		return value != null;
diff --git a/src/main/java/com/arangodb/tinkerpop/gremlin/structure/ArangoDBGraph.java b/src/main/java/com/arangodb/tinkerpop/gremlin/structure/ArangoDBGraph.java
index d98d8bc..20a2b90 100644
--- a/src/main/java/com/arangodb/tinkerpop/gremlin/structure/ArangoDBGraph.java
+++ b/src/main/java/com/arangodb/tinkerpop/gremlin/structure/ArangoDBGraph.java
@@ -14,8 +14,8 @@
 
 import com.arangodb.entity.EdgeDefinition;
 import org.apache.commons.collections4.CollectionUtils;
-import org.apache.commons.configuration.Configuration;
-import org.apache.commons.configuration.ConfigurationConverter;
+import org.apache.commons.configuration2.Configuration;
+import org.apache.commons.configuration2.ConfigurationConverter;
 import org.apache.commons.lang3.StringUtils;
 import org.apache.tinkerpop.gremlin.process.computer.GraphComputer;
 import org.apache.tinkerpop.gremlin.structure.Edge;
@@ -161,6 +161,21 @@
 		test = "org.apache.tinkerpop.gremlin.structure.util.detached.DetachedGraphTest",
 		method = "testAttachableCreateMethod",
 		reason = "test creates id without label prefix")
+@Graph.OptOut(
+		test = "org.apache.tinkerpop.gremlin.structure.PropertyTest$BasicPropertyTest",
+		method = "shouldAllowNullAddVertexProperty",
+		reason = "Cannot distinguish between null and not present properties."
+)
+@Graph.OptOut(
+		test = "org.apache.tinkerpop.gremlin.structure.PropertyTest$BasicPropertyTest",
+		method = "shouldAllowNullAddVertex",
+		reason = "Cannot distinguish between null and not present properties."
+)
+@Graph.OptOut(
+		test = "org.apache.tinkerpop.gremlin.structure.PropertyTest$BasicPropertyTest",
+		method = "shouldAllowNullAddEdge",
+		reason = "Cannot distinguish between null and not present properties."
+)
 // FIXME, OptOut failing tests
 @Graph.OptOut(
 		test = "org.apache.tinkerpop.gremlin.structure.GraphTest",
@@ -175,11 +190,11 @@
 		method = "shouldAllowIdAssignment",
 		reason = "FIXME")
 @Graph.OptOut(
-		test = "org.apache.tinkerpop.gremlin.structure.SerializationTest$GryoV3d0Test",
+		test = "org.apache.tinkerpop.gremlin.structure.SerializationTest$GryoV3Test",
 		method = "shouldSerializeTree",
 		reason = "FIXME")
 @Graph.OptOut(
-		test = "org.apache.tinkerpop.gremlin.structure.SerializationTest$GryoV1d0Test",
+		test = "org.apache.tinkerpop.gremlin.structure.SerializationTest$GryoV1Test",
 		method = "shouldSerializeTree",
 		reason = "FIXME")
 @Graph.OptOut(
diff --git a/src/main/java/com/arangodb/tinkerpop/gremlin/structure/ArangoDBVertex.java b/src/main/java/com/arangodb/tinkerpop/gremlin/structure/ArangoDBVertex.java
index 13a5639..ad3c589 100644
--- a/src/main/java/com/arangodb/tinkerpop/gremlin/structure/ArangoDBVertex.java
+++ b/src/main/java/com/arangodb/tinkerpop/gremlin/structure/ArangoDBVertex.java
@@ -19,7 +19,7 @@
 import java.util.regex.Matcher;
 import java.util.stream.Collectors;
 
-import org.apache.commons.lang.ArrayUtils;
+import org.apache.commons.lang3.ArrayUtils;
 import org.apache.tinkerpop.gremlin.structure.Direction;
 import org.apache.tinkerpop.gremlin.structure.Edge;
 import org.apache.tinkerpop.gremlin.structure.Graph;
@@ -38,7 +38,6 @@
 import com.arangodb.tinkerpop.gremlin.client.ArangoDBIterator;
 import com.arangodb.tinkerpop.gremlin.client.ArangoDBPropertyFilter;
 import com.arangodb.tinkerpop.gremlin.client.ArangoDBPropertyIterator;
-import com.arangodb.tinkerpop.gremlin.client.ArangoDBQueryBuilder;
 import com.arangodb.tinkerpop.gremlin.utils.ArangoDBUtil;
 
 
diff --git a/src/main/java/com/arangodb/tinkerpop/gremlin/utils/ArangoDBConfigurationBuilder.java b/src/main/java/com/arangodb/tinkerpop/gremlin/utils/ArangoDBConfigurationBuilder.java
index fd9d4f8..238ffaa 100644
--- a/src/main/java/com/arangodb/tinkerpop/gremlin/utils/ArangoDBConfigurationBuilder.java
+++ b/src/main/java/com/arangodb/tinkerpop/gremlin/utils/ArangoDBConfigurationBuilder.java
@@ -15,7 +15,8 @@
 import java.util.Set;
 import java.util.stream.Collectors;
 
-import org.apache.commons.configuration.BaseConfiguration;
+import org.apache.commons.configuration2.BaseConfiguration;
+import org.apache.commons.configuration2.convert.LegacyListDelimiterHandler;
 import org.apache.commons.lang3.tuple.ImmutableTriple;
 import org.apache.commons.lang3.tuple.Triple;
 import org.apache.tinkerpop.gremlin.structure.Graph;
@@ -123,12 +124,12 @@ public ArangoDBConfigurationBuilder() {
 	 * Build the configuration.
 	 *
 	 * @return a configuration that can be used to instantiate a new {@link ArangoDBGraph}.
-	 * @see ArangoDBGraph#open(org.apache.commons.configuration.Configuration)
+	 * @see ArangoDBGraph#open(org.apache.commons.configuration2.Configuration)
 	 */
 	
 	public BaseConfiguration build() {
 		BaseConfiguration config = new BaseConfiguration();
-		config.setListDelimiter('/');
+		config.setListDelimiterHandler(new LegacyListDelimiterHandler('/'));
 		config.addProperty(fullPropertyKey(ArangoDBGraph.PROPERTY_KEY_DB_NAME), dbName);
 		config.addProperty(fullPropertyKey(ArangoDBGraph.PROPERTY_KEY_GRAPH_NAME), graphName);
 		config.addProperty(fullPropertyKey(ArangoDBGraph.PROPERTY_KEY_VERTICES), vertices);
diff --git a/src/test/java/com/arangodb/tinkerpop/gremlin/ArangoDBGraphProvider.java b/src/test/java/com/arangodb/tinkerpop/gremlin/ArangoDBGraphProvider.java
index 043c1ec..fff483c 100644
--- a/src/test/java/com/arangodb/tinkerpop/gremlin/ArangoDBGraphProvider.java
+++ b/src/test/java/com/arangodb/tinkerpop/gremlin/ArangoDBGraphProvider.java
@@ -6,8 +6,8 @@
 import java.util.Set;
 
 import com.arangodb.tinkerpop.gremlin.structure.*;
-import org.apache.commons.configuration.Configuration;
-import org.apache.commons.configuration.ConfigurationConverter;
+import org.apache.commons.configuration2.Configuration;
+import org.apache.commons.configuration2.ConfigurationConverter;
 import org.apache.tinkerpop.gremlin.AbstractGraphProvider;
 import org.apache.tinkerpop.gremlin.LoadGraphWith;
 import org.apache.tinkerpop.gremlin.LoadGraphWith.GraphData;
@@ -192,6 +192,7 @@ else if (testMethodName.startsWith("shouldThrowOnGraphAddEdge")) {
 				case "shouldValidateEquality":
 				case "shouldHaveExceptionConsistencyWhenAssigningSameIdOnEdge":
 				case "shouldAddEdgeWithUserSuppliedStringId":
+				case "shouldAllowNullAddEdge":
 					builder.withEdgeCollection("self");
 					break;
 				case "shouldAllowRemovalFromEdgeWhenAlreadyRemoved":
@@ -222,6 +223,7 @@ else if (testMethodName.startsWith("shouldThrowOnGraphAddEdge")) {
 					builder.withEdgeCollection("created");
 					break;
 				case "shouldAddVertexWithLabel":
+				case "shouldAllowNullAddVertexProperty":
 					builder.withVertexCollection("person");
 					break;
 				case "shouldNotAllowSetProperty":
@@ -258,6 +260,14 @@ else if (testMethodName.startsWith("shouldThrowOnGraphAddEdge")) {
 						builder.withVertexCollection("foo");
 					}
 					break;
+				case "shouldHaveExceptionConsistencyWhenUsingNullVertexLabelOnOverload":
+				case "shouldHaveExceptionConsistencyWhenUsingNullVertexLabel":
+					builder.withVertexCollection("foo");
+					break;
+				case "shouldReadGraphMLWithCommonVertexAndEdgePropertyNames":
+					builder.withEdgeCollection("created");
+					builder.withEdgeCollection("knows");
+					break;
 				default:
 					System.out.println("case \"" + testMethodName + "\":");
 				}
diff --git a/src/test/java/com/arangodb/tinkerpop/gremlin/ArangoDBTestSuite.java b/src/test/java/com/arangodb/tinkerpop/gremlin/ArangoDBTestSuite.java
index 81a9fc3..a60343c 100644
--- a/src/test/java/com/arangodb/tinkerpop/gremlin/ArangoDBTestSuite.java
+++ b/src/test/java/com/arangodb/tinkerpop/gremlin/ArangoDBTestSuite.java
@@ -4,16 +4,7 @@
 import org.apache.tinkerpop.gremlin.algorithm.generator.CommunityGeneratorTest;
 import org.apache.tinkerpop.gremlin.algorithm.generator.DistributionGeneratorTest;
 import org.apache.tinkerpop.gremlin.process.traversal.TraversalEngine;
-import org.apache.tinkerpop.gremlin.structure.VertexTest;
-import org.apache.tinkerpop.gremlin.structure.EdgeTest;
-import org.apache.tinkerpop.gremlin.structure.FeatureSupportTest;
-import org.apache.tinkerpop.gremlin.structure.GraphConstructionTest;
-import org.apache.tinkerpop.gremlin.structure.GraphTest;
-import org.apache.tinkerpop.gremlin.structure.PropertyTest;
-import org.apache.tinkerpop.gremlin.structure.SerializationTest;
-import org.apache.tinkerpop.gremlin.structure.TransactionTest;
-import org.apache.tinkerpop.gremlin.structure.VariablesTest;
-import org.apache.tinkerpop.gremlin.structure.VertexPropertyTest;
+import org.apache.tinkerpop.gremlin.structure.*;
 import org.apache.tinkerpop.gremlin.structure.io.IoCustomTest;
 import org.apache.tinkerpop.gremlin.structure.io.IoEdgeTest;
 import org.apache.tinkerpop.gremlin.structure.io.IoGraphTest;
@@ -59,19 +50,16 @@ public class ArangoDBTestSuite extends AbstractGremlinSuite {
      */
     private static final Class<?>[] allTests = new Class<?>[]{
     	CommunityGeneratorTest.class,
-    	// Missing
         DetachedGraphTest.class,
         DetachedEdgeTest.class,
         DetachedVertexPropertyTest.class,
         DetachedPropertyTest.class,
         DetachedVertexTest.class,
-        // Missing
-        
         DistributionGeneratorTest.class,
         EdgeTest.class,
         FeatureSupportTest.class,
         IoCustomTest.class,
-        IoEdgeTest.class,		
+        IoEdgeTest.class,
         IoGraphTest.class,
         IoVertexTest.class,
         IoPropertyTest.class,
@@ -88,6 +76,7 @@ public class ArangoDBTestSuite extends AbstractGremlinSuite {
         SerializationTest.class,
         StarGraphTest.class,
         TransactionTest.class,
+		TransactionMultiThreadedTest.class,
         VertexTest.class,
          //ArangoDBIndexCheck.class,
          //ArangoDBCypherCheck.class,
diff --git a/src/test/java/com/arangodb/tinkerpop/gremlin/Issue57.java b/src/test/java/com/arangodb/tinkerpop/gremlin/Issue57.java
index db75c84..752d726 100644
--- a/src/test/java/com/arangodb/tinkerpop/gremlin/Issue57.java
+++ b/src/test/java/com/arangodb/tinkerpop/gremlin/Issue57.java
@@ -2,7 +2,7 @@
 
 import com.arangodb.tinkerpop.gremlin.structure.ArangoDBGraph;
 import com.arangodb.tinkerpop.gremlin.utils.ArangoDBConfigurationBuilder;
-import org.apache.commons.configuration.Configuration;
+import org.apache.commons.configuration2.Configuration;
 
 import java.io.File;
 
diff --git a/src/test/java/com/arangodb/tinkerpop/gremlin/client/test/BaseTestCase.java b/src/test/java/com/arangodb/tinkerpop/gremlin/client/test/BaseTestCase.java
index 777a717..6a2139c 100644
--- a/src/test/java/com/arangodb/tinkerpop/gremlin/client/test/BaseTestCase.java
+++ b/src/test/java/com/arangodb/tinkerpop/gremlin/client/test/BaseTestCase.java
@@ -3,8 +3,8 @@
 import java.util.Properties;
 
 import com.arangodb.tinkerpop.gremlin.client.ArangoDBGraphClient;
-import org.apache.commons.configuration.ConfigurationConverter;
-import org.apache.commons.configuration.PropertiesConfiguration;
+import org.apache.commons.configuration2.ConfigurationConverter;
+import org.apache.commons.configuration2.PropertiesConfiguration;
 import org.junit.After;
 import org.junit.Before;
 
diff --git a/src/test/java/com/arangodb/tinkerpop/gremlin/client/test/ClientTest.java b/src/test/java/com/arangodb/tinkerpop/gremlin/client/test/ClientTest.java
index 697b46c..b05af42 100644
--- a/src/test/java/com/arangodb/tinkerpop/gremlin/client/test/ClientTest.java
+++ b/src/test/java/com/arangodb/tinkerpop/gremlin/client/test/ClientTest.java
@@ -19,8 +19,8 @@
 import java.util.stream.Collectors;
 
 import com.arangodb.tinkerpop.gremlin.structure.ArangoDBGraph;
-import org.apache.commons.configuration.ConfigurationConverter;
-import org.apache.commons.configuration.PropertiesConfiguration;
+import org.apache.commons.configuration2.ConfigurationConverter;
+import org.apache.commons.configuration2.PropertiesConfiguration;
 import org.junit.*;
 import org.junit.rules.ExpectedException;
 import org.junit.runner.RunWith;
diff --git a/src/test/resources/logback-test.xml b/src/test/resources/logback-test.xml
index 284dba5..9e037b2 100644
--- a/src/test/resources/logback-test.xml
+++ b/src/test/resources/logback-test.xml
@@ -1,31 +1,31 @@
 <configuration>
 
-  <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
-    <!-- encoders are assigned the type
-         ch.qos.logback.classic.encoder.PatternLayoutEncoder by default -->
-    <encoder>
-      <pattern>%d{HH:mm:ss.SSS} %-5level %logger{36} - %msg%n</pattern>
-    </encoder>
-  </appender>
+    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
+        <!-- encoders are assigned the type
+             ch.qos.logback.classic.encoder.PatternLayoutEncoder by default -->
+        <encoder>
+            <pattern>%d{HH:mm:ss.SSS} %-5level %logger{36} - %msg%n</pattern>
+        </encoder>
+    </appender>
 
-  <appender name="FILE" class="ch.qos.logback.core.FileAppender">
-    <file>tikerpopTests.log</file>
-    <append>false</append>
-    <!-- set immediateFlush to false for much higher logging throughput -->
-    <immediateFlush>true</immediateFlush>
-    <!-- encoders are assigned the type
-         ch.qos.logback.classic.encoder.PatternLayoutEncoder by default -->
-    <encoder>
-      <pattern>%-4relative [%thread] %-5level %logger{35} - %msg%n</pattern>
-    </encoder>
-  </appender>
+    <appender name="FILE" class="ch.qos.logback.core.FileAppender">
+        <file>tikerpopTests.log</file>
+        <append>false</append>
+        <!-- set immediateFlush to false for much higher logging throughput -->
+        <immediateFlush>true</immediateFlush>
+        <!-- encoders are assigned the type
+             ch.qos.logback.classic.encoder.PatternLayoutEncoder by default -->
+        <encoder>
+            <pattern>%-4relative [%thread] %-5level %logger{35} - %msg%n</pattern>
+        </encoder>
+    </appender>
 
-  <root level="INFO">
-    <appender-ref ref="FILE" />
-    <appender-ref ref="STDOUT"/>
-  </root>
+    <root level="INFO">
+        <appender-ref ref="FILE" />
+        <appender-ref ref="STDOUT"/>
+    </root>
 
-<!--  <logger name="com.arangodb.internal.net.Communication" level="debug" />-->
-<!--  <logger name="com.arangodb.tinkerpop.gremlin.structure.ArangoDBEdge" level="debug" />-->
+    <!--  <logger name="com.arangodb.internal.net.Communication" level="debug" />-->
+    <!--  <logger name="com.arangodb.tinkerpop.gremlin.structure.ArangoDBEdge" level="debug" />-->
 
 </configuration>