diff --git a/core/src/main/java/hudson/model/Run.java b/core/src/main/java/hudson/model/Run.java
index 2cf8f9692e41db0f4fc6fe773aca71c25baf869e..582d8b55260e2effb460adfe51239c0b252aa067 100644
--- a/core/src/main/java/hudson/model/Run.java
+++ b/core/src/main/java/hudson/model/Run.java
@@ -654,7 +654,8 @@ public abstract class Run <JobT extends Job<JobT,RunT>,RunT extends Run<JobT,Run
      */
     public RunT getPreviousBuiltBuild() {
         RunT r=previousBuild;
-        while( r!=null && r.getResult()==Result.NOT_BUILT )
+        // in certain situations (aborted m2 builds) r.getResult() can still be null, although it should theoretically never happen
+        while( r!=null && (r.getResult() == null || r.getResult()==Result.NOT_BUILT) )
             r=r.previousBuild;
         return r;
     }