diff --git a/its/core-integration-testing-plugins/maven-it-plugin-project-interpolation/src/main/java/org/apache/maven/plugin/coreit/PropertyInterpolationMojo.java b/its/core-integration-testing-plugins/maven-it-plugin-project-interpolation/src/main/java/org/apache/maven/plugin/coreit/PropertyInterpolationMojo.java
index 20e8e5966a..136b44013f 100644
--- a/its/core-integration-testing-plugins/maven-it-plugin-project-interpolation/src/main/java/org/apache/maven/plugin/coreit/PropertyInterpolationMojo.java
+++ b/its/core-integration-testing-plugins/maven-it-plugin-project-interpolation/src/main/java/org/apache/maven/plugin/coreit/PropertyInterpolationMojo.java
@@ -50,7 +50,7 @@ public class PropertyInterpolationMojo
         
         if ( !value.equals( targetValue ) )
         {
-            throw new MojoExecutionException( "Property value of 'myDirectory': " + value + " should equal project build directory: " + project.getBuild().getDirectory() + " + '/foo'" );
+            throw new MojoExecutionException( "Property value of 'myDirectory': " + value + " should equal the 'foo' subpath of the project build directory: " + targetValue );
         }
     }
 }