diff --git a/cassovary-core/src/test/scala/com/twitter/cassovary/util/collections/CQueueSpec.scala b/cassovary-core/src/test/scala/com/twitter/cassovary/util/collections/CQueueSpec.scala
index f97ebf6f..d2b38695 100644
--- a/cassovary-core/src/test/scala/com/twitter/cassovary/util/collections/CQueueSpec.scala
+++ b/cassovary-core/src/test/scala/com/twitter/cassovary/util/collections/CQueueSpec.scala
@@ -21,6 +21,14 @@ class CQueueSpec extends WordSpec with Matchers {
     q.isEmpty should be (true)
 
     intercept[NoSuchElementException](q.deque())
+
+    // Check that fastutils were used
+    try {
+      q.deque()
+    } catch {
+      case e: Throwable =>
+        e.getStackTrace.head.getClassName.contains("it.unimi.dsi.fastutil") shouldEqual (true)
+    }
   }
 
   "CQueue" should {