diff --git a/build.sc b/build.sc
index 924cf8dc0..4364fbb1e 100644
--- a/build.sc
+++ b/build.sc
@@ -30,6 +30,9 @@ trait CommonDiffTest extends ScalaModule with SbtModule {
 
   override def scalacPluginIvyDeps = Agg(ivys.chisel3Plugin)
 
+  override def scalacOptions = Seq("-Ymacro-annotations") ++
+    Seq("-Xfatal-warnings", "-feature", "-deprecation", "-language:reflectiveCalls")
+
   override def ivyDeps = Agg(ivys.chisel3)
 }
 
diff --git a/src/main/scala/DPIC.scala b/src/main/scala/DPIC.scala
index 5c3c85059..62e0f54f4 100644
--- a/src/main/scala/DPIC.scala
+++ b/src/main/scala/DPIC.scala
@@ -63,7 +63,7 @@ class DPIC[T <: DifftestBundle](gen: T) extends ExtModule
     // This is different from BlackBoxes.
     io.elements.toSeq.reverse.map{ case (name, data) =>
       data match {
-        case vec: Vec[Data] => vec.zipWithIndex.map { case (v, i) => (s"io_${name}_$i", v) }
+        case vec: Vec[_] => vec.zipWithIndex.map { case (v, i) => (s"io_${name}_$i", v) }
         case _ => Seq((s"io_$name", data))
       }
     }
diff --git a/src/main/scala/Difftest.scala b/src/main/scala/Difftest.scala
index f547cdd04..fd1000056 100644
--- a/src/main/scala/Difftest.scala
+++ b/src/main/scala/Difftest.scala
@@ -88,7 +88,7 @@ abstract class DifftestBundle extends Bundle
     val raw = elements.toSeq.reverse.filterNot(e => filteredElements.contains(e._1))
     raw.map{ case (s, data) =>
       data match {
-        case v: Vec[UInt] => (s, Some(v))
+        case v: Vec[_] => (s, Some(v.asInstanceOf[Vec[UInt]]))
         case u: UInt => (s, Some(Seq(u)))
         case _ => println(s"Unknown type: ($s, $data)")
           (s, None)