diff --git a/src/main/scala/org/biodatageeks/rangejoins/methods/IntervalTree/IntervalTreeJoinOptimChromosome.scala b/src/main/scala/org/biodatageeks/rangejoins/methods/IntervalTree/IntervalTreeJoinOptimChromosome.scala
index a6b27883..88772d7e 100644
--- a/src/main/scala/org/biodatageeks/rangejoins/methods/IntervalTree/IntervalTreeJoinOptimChromosome.scala
+++ b/src/main/scala/org/biodatageeks/rangejoins/methods/IntervalTree/IntervalTreeJoinOptimChromosome.scala
@@ -34,7 +34,7 @@ case class IntervalTreeJoinOptimChromosome(left: SparkPlan,
                                            right: SparkPlan,
                                            condition: Seq[Expression],
                                            context: SparkSession,
-                                           minOverlap: Int, maxGap: Int, maxBroadcastSize : Int,
+                                           minOverlap: Int, maxGap: Int,
                                            useJoinOrder: Boolean
                                           ) extends BinaryExecNode with Serializable {
   @transient lazy val output = left.output ++ right.output
@@ -84,7 +84,7 @@ case class IntervalTreeJoinOptimChromosome(left: SparkPlan,
     if ( v1Size < v2Size ) {
       logger.warn(s"Broadcasting first table")
       val v3 = IntervalTreeJoinOptimChromosomeImpl.overlapJoin(context.sparkContext, v1kv, v2kv,
-         v1.count(), minOverlap, maxGap, maxBroadcastSize) //FIXME:can be further optimized!
+         v1.count(), minOverlap, maxGap) //FIXME:can be further optimized!
      v3.mapPartitions(
        p => {
          val joiner = GenerateUnsafeRowJoiner.create(left.schema, right.schema)
@@ -97,7 +97,7 @@ case class IntervalTreeJoinOptimChromosome(left: SparkPlan,
     else {
       logger.warn(s"Broadcasting second table")
       val v3 = IntervalTreeJoinOptimChromosomeImpl.overlapJoin(context.sparkContext, v2kv, v1kv,
-         v2.count(), minOverlap, maxGap, maxBroadcastSize)
+         v2.count(), minOverlap, maxGap)
       v3.mapPartitions(
         p => {
           val joiner = GenerateUnsafeRowJoiner.create(right.schema, left.schema)
diff --git a/src/main/scala/org/biodatageeks/rangejoins/methods/IntervalTree/IntervalTreeJoinOptimChromosomeImpl.scala b/src/main/scala/org/biodatageeks/rangejoins/methods/IntervalTree/IntervalTreeJoinOptimChromosomeImpl.scala
index 5b68a0cb..44ad04d5 100644
--- a/src/main/scala/org/biodatageeks/rangejoins/methods/IntervalTree/IntervalTreeJoinOptimChromosomeImpl.scala
+++ b/src/main/scala/org/biodatageeks/rangejoins/methods/IntervalTree/IntervalTreeJoinOptimChromosomeImpl.scala
@@ -60,7 +60,7 @@ object IntervalTreeJoinOptimChromosomeImpl extends Serializable {
   def overlapJoin(sc: SparkContext,
                   rdd1: RDD[(String,Interval[Int],InternalRow)],
                   rdd2: RDD[(String,Interval[Int],InternalRow)], rdd1Count:Long,
-                  minOverlap:Int, maxGap: Int, maxBroadCastSize: Int): RDD[(InternalRow, InternalRow)] = {
+                  minOverlap:Int, maxGap: Int): RDD[(InternalRow, InternalRow)] = {
 
     val logger =  Logger.getLogger(this.getClass.getCanonicalName)
 
@@ -73,7 +73,7 @@ object IntervalTreeJoinOptimChromosomeImpl extends Serializable {
       * https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4741060/
       */
 
-    val optimizer = new JoinOptimizerChromosome(sc,rdd1, rdd1Count, maxBroadCastSize)
+    val optimizer = new JoinOptimizerChromosome(sc,rdd1, rdd1Count)
     sc.setLogLevel("WARN")
     logger.warn(optimizer.debugInfo )
 
diff --git a/src/main/scala/org/biodatageeks/rangejoins/methods/IntervalTree/IntervalTreeJoinStrategyOptim.scala b/src/main/scala/org/biodatageeks/rangejoins/methods/IntervalTree/IntervalTreeJoinStrategyOptim.scala
index 58f729ac..0455fa13 100644
--- a/src/main/scala/org/biodatageeks/rangejoins/methods/IntervalTree/IntervalTreeJoinStrategyOptim.scala
+++ b/src/main/scala/org/biodatageeks/rangejoins/methods/IntervalTree/IntervalTreeJoinStrategyOptim.scala
@@ -24,7 +24,7 @@ class IntervalTreeJoinStrategyOptim(spark: SparkSession) extends Strategy with S
       spark.sparkContext.setLogLevel("WARN")
       /*register functions*/
       IntervalTreeJoinOptimChromosome(planLater(left), planLater(right),
-        rangeJoinKeys, spark, minOverlap.toInt, maxGap.toInt, maxBroadcastSize.toInt, useJoinOrder.toBoolean) :: Nil
+        rangeJoinKeys, spark, minOverlap.toInt, maxGap.toInt, useJoinOrder.toBoolean) :: Nil
     }
     case _ =>
       Nil
diff --git a/src/main/scala/org/biodatageeks/rangejoins/optimizer/JoinOptimizerChromosome.scala b/src/main/scala/org/biodatageeks/rangejoins/optimizer/JoinOptimizerChromosome.scala
index 43b0182d..4cc1c243 100644
--- a/src/main/scala/org/biodatageeks/rangejoins/optimizer/JoinOptimizerChromosome.scala
+++ b/src/main/scala/org/biodatageeks/rangejoins/optimizer/JoinOptimizerChromosome.scala
@@ -10,10 +10,16 @@ import org.biodatageeks.rangejoins.IntervalTree.{Interval, IntervalWithRow}
 import org.biodatageeks.rangejoins.optimizer.RangeJoinMethod.RangeJoinMethod
 
 
-class JoinOptimizerChromosome(sc: SparkContext, rdd: RDD[(String,Interval[Int],InternalRow)], rddCount : Long, maxBroadcastSize : Int) {
+class JoinOptimizerChromosome(sc: SparkContext, rdd: RDD[(String,Interval[Int],InternalRow)], rddCount : Long) {
 
 
-   val estBroadcastSize = estimateBroadcastSize(rdd,rddCount)
+  val maxBroadcastSize = sc
+    .getConf
+    .getOption("spark.biodatageeks.rangejoin.maxBroadcastSize") match {
+    case Some(size) => size.toLong
+    case _ => 0.1*scala.math.max((sc.getConf.getSizeAsBytes("spark.driver.memory","0")),1024*(1024*1024)) //defaults 128MB or 0.1 * Spark Driver's memory
+  }
+  val estBroadcastSize = estimateBroadcastSize(rdd,rddCount)
 
 
    private def estimateBroadcastSize(rdd: RDD[(String,Interval[Int],InternalRow)], rddCount: Long): Long = {
@@ -23,8 +29,8 @@ class JoinOptimizerChromosome(sc: SparkContext, rdd: RDD[(String,Interval[Int],I
 
   def debugInfo = {
     s"""
-       |Broadcast structure size is ~ ${estBroadcastSize/1024} kb
-       |spark.biodatageeks.rangejoin.maxBroadcastSize is set to ${maxBroadcastSize/1024} kb"
+       |Broadcast structure size is ~ ${math.rint(100*estBroadcastSize/1024.0)/100} kb
+       |spark.biodatageeks.rangejoin.maxBroadcastSize is set to ${(maxBroadcastSize/1024).toInt} kb"
        |Using ${getRangeJoinMethod.toString} join method
      """.stripMargin
   }
diff --git a/src/test/scala/pl/edu/pw/ii/biodatageeks/tests/FeatureCountsTestSuite.scala b/src/test/scala/pl/edu/pw/ii/biodatageeks/tests/FeatureCountsTestSuite.scala
index 6ebdd844..f49fcc92 100644
--- a/src/test/scala/pl/edu/pw/ii/biodatageeks/tests/FeatureCountsTestSuite.scala
+++ b/src/test/scala/pl/edu/pw/ii/biodatageeks/tests/FeatureCountsTestSuite.scala
@@ -54,6 +54,7 @@ class FeatureCountsTestSuite extends FunSuite with DataFrameSuiteBase with Befor
     targets
       .createOrReplaceTempView("targets")
 
+    spark.sql(query).explain(false)
     assert(spark.sql(query).first().getLong(0) === 1484L)
   }