diff --git a/graphx/src/main/scala/org/apache/spark/graphx/util/GraphGenerators.scala b/graphx/src/main/scala/org/apache/spark/graphx/util/GraphGenerators.scala
index b8309289fe475..8a13c74221546 100644
--- a/graphx/src/main/scala/org/apache/spark/graphx/util/GraphGenerators.scala
+++ b/graphx/src/main/scala/org/apache/spark/graphx/util/GraphGenerators.scala
@@ -118,7 +118,7 @@ object GraphGenerators {
       val Z = rand.nextGaussian()
       X = math.exp(mu + sigma*Z)
     }
-    math.round(X.toFloat)
+    math.floor(X).toInt
   }
 
   /**
diff --git a/graphx/src/test/scala/org/apache/spark/graphx/util/GraphGeneratorsSuite.scala b/graphx/src/test/scala/org/apache/spark/graphx/util/GraphGeneratorsSuite.scala
index b346d4db2ef96..3abefbe52fa8a 100644
--- a/graphx/src/test/scala/org/apache/spark/graphx/util/GraphGeneratorsSuite.scala
+++ b/graphx/src/test/scala/org/apache/spark/graphx/util/GraphGeneratorsSuite.scala
@@ -64,8 +64,11 @@ class GraphGeneratorsSuite extends FunSuite with LocalSparkContext {
     val sigma = 1.3
     val maxVal = 100
 
-    val dstId = GraphGenerators.sampleLogNormal(mu, sigma, maxVal)
-    assert(dstId < maxVal)
+    val trials = 1000
+    for (i <- 1 to trials) {
+      val dstId = GraphGenerators.sampleLogNormal(mu, sigma, maxVal)
+      assert(dstId < maxVal)
+    }
 
     val dstId_round1 = GraphGenerators.sampleLogNormal(mu, sigma, maxVal, 12345)
     val dstId_round2 = GraphGenerators.sampleLogNormal(mu, sigma, maxVal, 12345)