diff --git a/core/src/main/scala/chisel3/Aggregate.scala b/core/src/main/scala/chisel3/Aggregate.scala
index 3e6022c1d2c..e5a735914c3 100644
--- a/core/src/main/scala/chisel3/Aggregate.scala
+++ b/core/src/main/scala/chisel3/Aggregate.scala
@@ -1207,51 +1207,52 @@ abstract class Bundle(implicit compileOptions: CompileOptions) extends Record {
     *   assert(uint === "h12345678".U) // This will pass
     * }}}
     */
-  final lazy val elements: SeqMap[String, Data] = {
-    // _elementsImpl is a method, only call it once
-    val elementsImpl = _elementsImpl
-    val hardwareFields = elementsImpl.flatMap {
-      case (name, data: Data) =>
-        if (data.isSynthesizable) {
-          Some(s"$name: $data")
-        } else {
-          None
-        }
-      case (name, Some(data: Data)) =>
-        if (data.isSynthesizable) {
-          Some(s"$name: $data")
-        } else {
+  final lazy val elements: SeqMap[String, Data] = _elementsImpl match {
+    case reflective: VectorMap[String, Data] => reflective
+    // _elementsImpl is a method, only call it once, see the match above for the 1 call
+    case elementsImpl =>
+      val hardwareFields = elementsImpl.flatMap {
+        case (name, data: Data) =>
+          if (data.isSynthesizable) {
+            Some(s"$name: $data")
+          } else {
+            None
+          }
+        case (name, Some(data: Data)) =>
+          if (data.isSynthesizable) {
+            Some(s"$name: $data")
+          } else {
+            None
+          }
+        case (name, s: scala.collection.Seq[Any]) if s.nonEmpty =>
+          s.head match {
+            // Ignore empty Seq()
+            case d: Data =>
+              throwException(
+                "Public Seq members cannot be used to define Bundle elements " +
+                  s"(found public Seq member '${name}'). " +
+                  "Either use a Vec if all elements are of the same type, or MixedVec if the elements " +
+                  "are of different types. If this Seq member is not intended to construct RTL, mix in the trait " +
+                  "IgnoreSeqInBundle."
+              )
+            case _ => // don't care about non-Data Seq
+          }
           None
-        }
-      case (name, s: scala.collection.Seq[Any]) if s.nonEmpty =>
-        s.head match {
-          // Ignore empty Seq()
-          case d: Data =>
-            throwException(
-              "Public Seq members cannot be used to define Bundle elements " +
-                s"(found public Seq member '${name}'). " +
-                "Either use a Vec if all elements are of the same type, or MixedVec if the elements " +
-                "are of different types. If this Seq member is not intended to construct RTL, mix in the trait " +
-                "IgnoreSeqInBundle."
-            )
-          case _ => // don't care about non-Data Seq
-        }
-        None
 
-      case _ => None
-    }
-    if (hardwareFields.nonEmpty) {
-      throw ExpectedChiselTypeException(s"Bundle: $this contains hardware fields: " + hardwareFields.mkString(","))
-    }
-    VectorMap(elementsImpl.toSeq.flatMap {
-      case (name, data: Data) =>
-        Some(name -> data)
-      case (name, Some(data: Data)) =>
-        Some(name -> data)
-      case _ => None
-    }.sortWith {
-      case ((an, a), (bn, b)) => (a._id > b._id) || ((a eq b) && (an > bn))
-    }: _*)
+        case _ => None
+      }
+      if (hardwareFields.nonEmpty) {
+        throw ExpectedChiselTypeException(s"Bundle: $this contains hardware fields: " + hardwareFields.mkString(","))
+      }
+      VectorMap(elementsImpl.toSeq.flatMap {
+        case (name, data: Data) =>
+          Some(name -> data)
+        case (name, Some(data: Data)) =>
+          Some(name -> data)
+        case _ => None
+      }.sortWith {
+        case ((an, a), (bn, b)) => (a._id > b._id) || ((a eq b) && (an > bn))
+      }: _*)
   }
   /*
    * This method will be overwritten by the Chisel-Plugin
@@ -1261,7 +1262,8 @@ abstract class Bundle(implicit compileOptions: CompileOptions) extends Record {
     for (m <- getPublicFields(classOf[Bundle])) {
       getBundleField(m) match {
         case Some(d: Data) =>
-          // Checking for chiselType is done in elements method
+          requireIsChiselType(d)
+
           if (nameMap contains m.getName) {
             require(nameMap(m.getName) eq d)
           } else {