diff --git a/maven-plugin-testing-harness/src/main/java/org/apache/maven/plugin/testing/AbstractMojoTestCase.java b/maven-plugin-testing-harness/src/main/java/org/apache/maven/plugin/testing/AbstractMojoTestCase.java
index dec1a81..ae9f06f 100644
--- a/maven-plugin-testing-harness/src/main/java/org/apache/maven/plugin/testing/AbstractMojoTestCase.java
+++ b/maven-plugin-testing-harness/src/main/java/org/apache/maven/plugin/testing/AbstractMojoTestCase.java
@@ -111,7 +111,7 @@ public abstract class AbstractMojoTestCase
         XmlStreamReader reader = ReaderFactory.newXmlReader( is );
 
         InterpolationFilterReader interpolationFilterReader =
-            new InterpolationFilterReader( new BufferedReader( reader ), container.getContext().getContextData() );
+            new InterpolationFilterReader( new BufferedReader( reader ), ( Map ) container.getContext().getContextData() );
 
         PluginDescriptor pluginDescriptor = new PluginDescriptorBuilder().build( interpolationFilterReader );
 
diff --git a/pom.xml b/pom.xml
index 589682d..d77ef4f 100644
--- a/pom.xml
+++ b/pom.xml
@@ -182,7 +182,7 @@ under the License.
       <dependency>
         <groupId>org.codehaus.plexus</groupId>
         <artifactId>plexus-utils</artifactId>
-        <version>3.0.8</version>
+        <version>3.0.21</version>
         <scope>provided</scope>
       </dependency>