diff --git a/build.properties b/build.properties
index 9c841b62a0..c663459e6d 100644
--- a/build.properties
+++ b/build.properties
@@ -1,5 +1,5 @@
 classworlds.version=1.2-alpha-6
-plexus.version=1.0-alpha-15
+plexus.version=1.0-alpha-16-SNAPSHOT
 plexus-archiver.version=1.0-alpha-8
 plexus-utils.version=1.4-alpha-1
 plexus-interactivity-api.version=1.0-alpha-4
diff --git a/maven-artifact-ant/src/main/java/org/apache/maven/artifact/ant/AbstractArtifactTask.java b/maven-artifact-ant/src/main/java/org/apache/maven/artifact/ant/AbstractArtifactTask.java
index 3027b4d60d..8884ff4300 100755
--- a/maven-artifact-ant/src/main/java/org/apache/maven/artifact/ant/AbstractArtifactTask.java
+++ b/maven-artifact-ant/src/main/java/org/apache/maven/artifact/ant/AbstractArtifactTask.java
@@ -308,7 +308,7 @@ public abstract class AbstractArtifactTask
 
                     classWorld.newRealm( "plexus.core", getClass().getClassLoader() );
 
-                    container = new DefaultPlexusContainer( null, null, null, classWorld );
+                    container = new DefaultPlexusContainer( null, null, classWorld );
 
                 }
                 catch ( PlexusContainerException e )
diff --git a/maven-embedder/pom.xml b/maven-embedder/pom.xml
index ac3b13fb74..e9c3e130f7 100644
--- a/maven-embedder/pom.xml
+++ b/maven-embedder/pom.xml
@@ -70,6 +70,10 @@
       <artifactId>maven-core</artifactId>
       <version>2.1-SNAPSHOT</version>
     </dependency>
+    <dependency>
+      <groupId>org.codehaus.plexus</groupId>
+      <artifactId>plexus-container-default</artifactId>
+    </dependency>
     <dependency>
       <groupId>org.apache.maven</groupId>
       <artifactId>maven-tools</artifactId>
diff --git a/maven-embedder/src/main/java/org/apache/maven/embedder/MavenEmbedder.java b/maven-embedder/src/main/java/org/apache/maven/embedder/MavenEmbedder.java
index e61b631887..999c526448 100644
--- a/maven-embedder/src/main/java/org/apache/maven/embedder/MavenEmbedder.java
+++ b/maven-embedder/src/main/java/org/apache/maven/embedder/MavenEmbedder.java
@@ -382,7 +382,7 @@ public class MavenEmbedder
 
         try
         {
-            container = new DefaultPlexusContainer( null, null, null, classWorld );
+            container = new DefaultPlexusContainer( null, null, classWorld );
         }
         catch ( PlexusContainerException e )
         {
diff --git a/pom.xml b/pom.xml
index 0303e8c299..3c136f8358 100644
--- a/pom.xml
+++ b/pom.xml
@@ -147,7 +147,7 @@
   </modules>
   <properties>
     <wagonVersion>1.0-beta-2</wagonVersion>
-    <plexusVersion>1.0-alpha-15</plexusVersion>
+    <plexusVersion>1.0-alpha-16-SNAPSHOT</plexusVersion>
   </properties>
   <dependencies>
     <dependency>
@@ -172,7 +172,7 @@
       <dependency>
         <groupId>org.codehaus.plexus</groupId>
         <artifactId>plexus-classworlds</artifactId>
-        <version>1.2-alpha-6</version>
+        <version>1.2-alpha-7-SNAPSHOT</version>
       </dependency>
       <dependency>
         <groupId>org.codehaus.plexus</groupId>