diff --git a/free/src/main/scala/cats/free/FreeApplicative.scala b/free/src/main/scala/cats/free/FreeApplicative.scala
index b147fab310..710f44dff3 100644
--- a/free/src/main/scala/cats/free/FreeApplicative.scala
+++ b/free/src/main/scala/cats/free/FreeApplicative.scala
@@ -155,12 +155,12 @@ object FreeApplicative {
 
   // Internal helper function for foldMap, it folds only Pure and Lift nodes
   private[free] def foldArg[F[_], G[_], A](node: FA[F, A], f: F ~> G)(implicit G: Applicative[G]): G[A] = {
-    node match {
-      case Pure(x) =>
-        G.pure(x)
-      case Lift(fa) =>
-        f(fa)
-      case _ => sys.error("\"impossible\", foldArg should be called on Pure or Lift nodes only")
+    if (node.isInstanceOf[Pure[F, A]]) {
+      val Pure(x) = node
+      G.pure(x)
+    } else {
+      val Lift(fa) = node
+      f(fa)
     }
   }