diff --git a/compiler/src/dotty/tools/dotc/core/TypeErasure.scala b/compiler/src/dotty/tools/dotc/core/TypeErasure.scala
index b62327f8b103..321ef835ae78 100644
--- a/compiler/src/dotty/tools/dotc/core/TypeErasure.scala
+++ b/compiler/src/dotty/tools/dotc/core/TypeErasure.scala
@@ -320,6 +320,7 @@ object TypeErasure {
         case _ => false
       }
     case tp: TypeParamRef => false
+    case tp: TypeBounds => false
     case tp: TypeProxy => hasStableErasure(tp.superType)
     case tp: AndOrType => hasStableErasure(tp.tp1) && hasStableErasure(tp.tp2)
     case _ => false
diff --git a/compiler/src/dotty/tools/dotc/typer/Implicits.scala b/compiler/src/dotty/tools/dotc/typer/Implicits.scala
index d35852a2b2e8..07377aea17a5 100644
--- a/compiler/src/dotty/tools/dotc/typer/Implicits.scala
+++ b/compiler/src/dotty/tools/dotc/typer/Implicits.scala
@@ -564,7 +564,7 @@ trait Implicits { self: Typer =>
      *  synthesize a class tag for `T`.
    	 */
     def synthesizedClassTag(formal: Type)(implicit ctx: Context): Tree =
-      formal.argTypes match {
+      formal.argInfos match {
         case arg :: Nil =>
           fullyDefinedType(arg, "ClassTag argument", pos) match {
             case defn.ArrayOf(elemTp) =>
diff --git a/tests/neg/i3630.scala b/tests/neg/i3630.scala
new file mode 100644
index 000000000000..2ca36cdffc16
--- /dev/null
+++ b/tests/neg/i3630.scala
@@ -0,0 +1 @@
+class U { Array(Array(2), Array("a")) } // error: no classtag