diff --git a/core/api/src/main/java/org/onosproject/net/topology/AbstractPathService.java b/core/api/src/main/java/org/onosproject/net/topology/AbstractPathService.java
index d718d15..8b24cbb 100644
--- a/core/api/src/main/java/org/onosproject/net/topology/AbstractPathService.java
+++ b/core/api/src/main/java/org/onosproject/net/topology/AbstractPathService.java
@@ -239,6 +239,9 @@
             primary = path.primary();
             backup = path.backup();
         }
+        if (backup == null) {
+        return new DefaultDisjointPath(PID, (DefaultPath) edgeToEdgePath(srcLink, dstLink, primary));
+        }
         return new DefaultDisjointPath(PID, (DefaultPath) edgeToEdgePath(srcLink, dstLink, primary),
                                        (DefaultPath) edgeToEdgePath(srcLink, dstLink, backup));
     }