diff --git a/util/relation/src/test/scala/RelationTest.scala b/util/relation/src/test/scala/RelationTest.scala
index de63fe893..03b728915 100644
--- a/util/relation/src/test/scala/RelationTest.scala
+++ b/util/relation/src/test/scala/RelationTest.scala
@@ -52,7 +52,7 @@ object RelationTest extends Properties("Relation")
 	}
 
 	property("Groups correctly") = forAll { (entries: List[(Int, Double)], randomInt: Int) =>
-		val splitInto = randomInt % 10 + 1  // Split into 1-10 groups.
+		val splitInto = math.abs(randomInt) % 10 + 1  // Split into 1-10 groups.
 		val rel = Relation.empty[Int, Double] ++ entries
 		val grouped = rel groupBy (_._1 % splitInto)
 		all(grouped.toSeq) {