diff --git a/library/collection/List.scala b/library/collection/List.scala
index daae8ef42bc94c7fa962114aaa3da1e4f27ee542..e2d0a14273a6b2fa3b74c0440ffda3e147cc3c93 100644
--- a/library/collection/List.scala
+++ b/library/collection/List.scala
@@ -342,7 +342,7 @@ sealed abstract class List[T] {
 
   def rotate(s: BigInt): List[T] = {
     if (isEmpty) {
-      Nil()
+      Nil[T]()
     } else if (s < 0) {
       rotate(size+s)
     } else {
diff --git a/src/main/scala/leon/frontends/scalac/CodeExtraction.scala b/src/main/scala/leon/frontends/scalac/CodeExtraction.scala
index aa1e14430bba79f18d7000cfa8eb68f6df8a4231..0741d2b4bfa2131c7445c5638ac330c578763c06 100644
--- a/src/main/scala/leon/frontends/scalac/CodeExtraction.scala
+++ b/src/main/scala/leon/frontends/scalac/CodeExtraction.scala
@@ -896,7 +896,7 @@ trait CodeExtraction extends ASTExtractors {
         }} else body0
 
       val finalBody = try {
-        flattenBlocks(extractTree(body)(fctx)) match {
+        flattenBlocks(extractTreeOrNoTree(body)(fctx)) match {
           case e if e.getType.isInstanceOf[ArrayType] =>
             getOwner(e) match {
               case Some(Some(fd)) if fd == funDef =>