diff --git a/src/main/java/org/jenkinsci/plugins/junitrealtimetestreporter/Attacher.java b/src/main/java/org/jenkinsci/plugins/junitrealtimetestreporter/Attacher.java
index 7ec5733..27dd6d2 100644
--- a/src/main/java/org/jenkinsci/plugins/junitrealtimetestreporter/Attacher.java
+++ b/src/main/java/org/jenkinsci/plugins/junitrealtimetestreporter/Attacher.java
@@ -40,7 +40,9 @@ public class Attacher extends RunListener<Run<?, ?>> {
 
     @Override
     public void onStarted(Run<?, ?> run, TaskListener listener) {
-
+        if ( !( run instanceof AbstractBuild )) {
+            return;
+        }
         final AbstractBuild<?, ?> build = (AbstractBuild<?, ?>) run;
 
         if (!isApplicable(build)) return;
@@ -66,4 +68,4 @@ private static boolean isApplicable(final AbstractBuild<?, ?> build) {
 
         return true;
     }
-}
\ No newline at end of file
+}