diff --git a/src/main/scala/leon/purescala/TreeOps.scala b/src/main/scala/leon/purescala/TreeOps.scala
index 86f33d7b2045631ca300449ab03cb9cdcc3030dd..124b163d99f38f4c7c131df0dca03acfda61e132 100644
--- a/src/main/scala/leon/purescala/TreeOps.scala
+++ b/src/main/scala/leon/purescala/TreeOps.scala
@@ -93,7 +93,7 @@ object TreeOps {
    *   f(a), f(b), f(c), f(Minus(b, c)), f(Add(a, Minus(b, c)))
    */
   def postTraversal(f: Expr => Unit)(e: Expr): Unit = {
-    val rec = preTraversal(f) _
+    val rec = postTraversal(f) _
 
     e match {
       case t: Terminal =>