diff --git a/graphx/src/main/scala/org/apache/spark/graphx/impl/RoutingTable.scala b/graphx/src/main/scala/org/apache/spark/graphx/impl/RoutingTable.scala
index fe44e1ee0c391..022d5668e2942 100644
--- a/graphx/src/main/scala/org/apache/spark/graphx/impl/RoutingTable.scala
+++ b/graphx/src/main/scala/org/apache/spark/graphx/impl/RoutingTable.scala
@@ -69,9 +69,9 @@ class RoutingTable(edges: EdgeRDD[_], vertices: VertexRDD[_]) {
       vSet.iterator.map { vid => (vid, pid) }
     }
 
-    val numPartitions = vertices.partitions.size
+    val numEdgePartitions = edges.partitions.size
     vid2pid.partitionBy(vertices.partitioner.get).mapPartitions { iter =>
-      val pid2vid = Array.fill(numPartitions)(new PrimitiveVector[VertexId])
+      val pid2vid = Array.fill(numEdgePartitions)(new PrimitiveVector[VertexId])
       for ((vid, pid) <- iter) {
         pid2vid(pid) += vid
       }
diff --git a/graphx/src/test/scala/org/apache/spark/graphx/GraphSuite.scala b/graphx/src/test/scala/org/apache/spark/graphx/GraphSuite.scala
index d9ba4672ce0c5..32b5fe4813594 100644
--- a/graphx/src/test/scala/org/apache/spark/graphx/GraphSuite.scala
+++ b/graphx/src/test/scala/org/apache/spark/graphx/GraphSuite.scala
@@ -297,4 +297,16 @@ class GraphSuite extends FunSuite with LocalSparkContext {
     }
   }
 
+  test("more edge partitions than vertex partitions") {
+    withSpark { sc =>
+      val verts = sc.parallelize(List((1: VertexId, "a"), (2: VertexId, "b")), 1)
+      val edges = sc.parallelize(List(Edge(1, 2, 0), Edge(2, 1, 0)), 2)
+      val graph = Graph(verts, edges)
+      val triplets = graph.triplets.map(et => (et.srcId, et.dstId, et.srcAttr, et.dstAttr))
+        .collect.toSet
+      assert(triplets ===
+        Set((1: VertexId, 2: VertexId, "a", "b"), (2: VertexId, 1: VertexId, "b", "a")))
+    }
+  }
+
 }